src/img2pdf.py

@@ -85,9 +85,9 @@ FitMode = Enum("FitMode", "into fill exact shrink enlarge")
 
 PageOrientation = Enum("PageOrientation", "portrait landscape")
 
-Colorspace = Enum("Colorspace", "RGB L 1 CMYK CMYK;I RGBA P other")
+Colorspace = Enum("Colorspace", "RGB RGBA L LA 1 CMYK CMYK;I P other")
 
-ImageFormat = Enum("ImageFormat", "JPEG JPEG2000 CCITTGroup4 PNG TIFF MPO other")
+ImageFormat = Enum("ImageFormat", "JPEG JPEG2000 CCITTGroup4 PNG GIF TIFF MPO other")
 
 PageMode = Enum("PageMode", "none outlines thumbs")
 
@@ -742,6 +742,7 @@ class pdfdoc(object):
         imgheightpx,
         imgformat,
         imgdata,
+        smaskdata,
         imgwidthpdf,
         imgheightpdf,
         imgxpdf,
@@ -759,6 +760,11 @@ class pdfdoc(object):
         artborder=None,
         iccp=None,
     ):
+        assert (
+            (color != Colorspace.RGBA and color != Colorspace.LA)
+            or (imgformat == ImageFormat.PNG and smaskdata is not None)
+        )
+
         if self.engine == Engine.pikepdf:
             PdfArray = pikepdf.Array
             PdfDict = pikepdf.Dictionary
@@ -777,9 +783,9 @@ class pdfdoc(object):
         TrueObject = True if self.engine == Engine.pikepdf else PdfObject("true")
         FalseObject = False if self.engine == Engine.pikepdf else PdfObject("false")
 
-        if color == Colorspace["1"] or color == Colorspace.L:
+        if color == Colorspace["1"] or color == Colorspace.L or color == Colorspace.LA:
             colorspace = PdfName.DeviceGray
-        elif color == Colorspace.RGB:
+        elif color == Colorspace.RGB or color == Colorspace.RGBA:
             colorspace = PdfName.DeviceRGB
         elif color == Colorspace.CMYK or color == Colorspace["CMYK;I"]:
             colorspace = PdfName.DeviceCMYK
@@ -816,9 +822,9 @@ class pdfdoc(object):
             else:
                 iccpdict = PdfDict(stream=convert_load(iccp))
             iccpdict[PdfName.Alternate] = colorspace
-            if color == Colorspace["1"] or color == Colorspace.L:
+            if color == Colorspace["1"] or color == Colorspace.L or color == Colorspace.LA:
                 iccpdict[PdfName.N] = 1
-            elif color == Colorspace.RGB:
+            elif color == Colorspace.RGB or color == Colorspace.RGBA:
                 iccpdict[PdfName.N] = 3
             elif color == Colorspace.CMYK or color == Colorspace["CMYK;I"]:
                 iccpdict[PdfName.N] = 4
@@ -852,6 +858,8 @@ class pdfdoc(object):
         image[PdfName.ColorSpace] = colorspace
         image[PdfName.BitsPerComponent] = depth
 
+        smask = None
+
         if color == Colorspace["CMYK;I"]:
             # Inverts all four channels
             image[PdfName.Decode] = [1, 0, 1, 0, 1, 0, 1, 0]
@@ -869,9 +877,35 @@ class pdfdoc(object):
             decodeparms[PdfName.Rows] = imgheightpx
             image[PdfName.DecodeParms] = [decodeparms]
         elif imgformat is ImageFormat.PNG:
+            if smaskdata is not None:
+                if self.engine == Engine.pikepdf:
+                    smask = self.writer.make_stream(smaskdata)
+                else:
+                    smask = PdfDict(stream=convert_load(smaskdata))
+                smask[PdfName.Type] = PdfName.XObject
+                smask[PdfName.Subtype] = PdfName.Image
+                smask[PdfName.Filter] = PdfName.FlateDecode
+                smask[PdfName.Width] = imgwidthpx
+                smask[PdfName.Height] = imgheightpx
+                smask[PdfName.ColorSpace] = PdfName.DeviceGray
+                smask[PdfName.BitsPerComponent] = depth
+
+                decodeparms = PdfDict()
+                decodeparms[PdfName.Predictor] = 15
+                decodeparms[PdfName.Colors] = 1
+                decodeparms[PdfName.Columns] = imgwidthpx
+                decodeparms[PdfName.BitsPerComponent] = depth
+                smask[PdfName.DecodeParms] = decodeparms
+
+                image[PdfName.SMask] = smask
+
+                # /SMask requires PDF 1.4
+                if self.output_version < "1.4":
+                    self.output_version = "1.4"
+
             decodeparms = PdfDict()
             decodeparms[PdfName.Predictor] = 15
-            if color in [Colorspace.P, Colorspace["1"], Colorspace.L]:
+            if color in [Colorspace.P, Colorspace["1"], Colorspace.L, Colorspace.LA]:
                 decodeparms[PdfName.Colors] = 1
             else:
                 decodeparms[PdfName.Colors] = 3
@@ -954,6 +988,8 @@ class pdfdoc(object):
             if self.engine == Engine.internal:
                 self.writer.addobj(content)
                 self.writer.addobj(image)
+                if smask is not None:
+                    self.writer.addobj(smask)
                 if iccp is not None:
                     self.writer.addobj(iccpdict)
 
@@ -1183,8 +1219,21 @@ def get_imgmetadata(
         # Search online for the 72.009 dpi problem for more info.
         ndpi = (int(round(ndpi[0])), int(round(ndpi[1])))
         ics = imgdata.mode
-
+    
-    if ics in ["LA", "PA", "RGBA"] or "transparency" in imgdata.info:
+    # GIF and PNG files with transparency are supported
+    if (
+        (imgformat == ImageFormat.PNG or imgformat == ImageFormat.GIF)
+        and (ics in ["RGBA", "LA"] or "transparency" in imgdata.info)
+    ):
+        # Must check the IHDR chunk for the bit depth, because PIL would lossily
+        # convert 16-bit RGBA/LA images to 8-bit.
+        if imgformat == ImageFormat.PNG and rawdata is not None:
+            depth = rawdata[24]
+            if depth > 8:
+                logger.warning("Image with transparency and a bit depth of %d." % depth)
+                logger.warning("This is unsupported due to PIL limitations.")
+                raise AlphaChannelError("Refusing to work with multiple >8bit channels.")
+    elif (ics in ["LA", "PA", "RGBA"] or "transparency" in imgdata.info):
         logger.warning("Image contains transparency which cannot be retained in PDF.")
         logger.warning("img2pdf will not perform a lossy operation.")
         logger.warning("You can remove the alpha channel using imagemagick:")
@@ -1427,6 +1476,7 @@ def read_images(rawdata, colorspace, first_frame_only=False, rot=None):
                 ndpi,
                 imgformat,
                 rawdata,
+                None,
                 imgwidthpx,
                 imgheightpx,
                 [],
@@ -1483,6 +1533,7 @@ def read_images(rawdata, colorspace, first_frame_only=False, rot=None):
                     ndpi,
                     ImageFormat.JPEG,
                     rawdata[offset : offset + mpent["Size"]],
+                    None,
                     imgwidthpx,
                     imgheightpx,
                     [],
@@ -1507,31 +1558,37 @@ def read_images(rawdata, colorspace, first_frame_only=False, rot=None):
         color, ndpi, imgwidthpx, imgheightpx, rotation, iccp = get_imgmetadata(
             imgdata, imgformat, default_dpi, colorspace, rawdata, rot
         )
-        pngidat, palette = parse_png(rawdata)
+        if (
-        # PIL does not provide the information about the original bits per
+            color != Colorspace.RGBA
-        # sample. Thus, we retrieve that info manually by looking at byte 9 in
+            and color != Colorspace.LA
-        # the IHDR chunk. We know where to find that in the file because the
+            and "transparency" not in imgdata.info
-        # IHDR chunk must be the first chunk
+        ):
-        depth = rawdata[24]
+            pngidat, palette = parse_png(rawdata)
-        if depth not in [1, 2, 4, 8, 16]:
+            # PIL does not provide the information about the original bits per
-            raise ValueError("invalid bit depth: %d" % depth)
+            # sample. Thus, we retrieve that info manually by looking at byte 9 in
-        logger.debug("read_images() embeds a PNG")
+            # the IHDR chunk. We know where to find that in the file because the
-        cleanup()
+            # IHDR chunk must be the first chunk
-        return [
+            depth = rawdata[24]
-            (
+            if depth not in [1, 2, 4, 8, 16]:
-                color,
+                raise ValueError("invalid bit depth: %d" % depth)
-                ndpi,
+            logger.debug("read_images() embeds a PNG")
-                imgformat,
+            cleanup()
-                pngidat,
+            return [
-                imgwidthpx,
+                (
-                imgheightpx,
+                    color,
-                palette,
+                    ndpi,
-                False,
+                    imgformat,
-                depth,
+                    pngidat,
-                rotation,
+                    None,
-                iccp,
+                    imgwidthpx,
-            )
+                    imgheightpx,
-        ]
+                    palette,
+                    False,
+                    depth,
+                    rotation,
+                    iccp,
+                )
+            ]
 
     # If our input is not JPEG or PNG, then we might have a format that
     # supports multiple frames (like TIFF or GIF), so we need a loop to
@@ -1615,6 +1672,7 @@ def read_images(rawdata, colorspace, first_frame_only=False, rot=None):
                     ndpi,
                     ImageFormat.CCITTGroup4,
                     rawdata,
+                    None,
                     imgwidthpx,
                     imgheightpx,
                     [],
@@ -1644,6 +1702,7 @@ def read_images(rawdata, colorspace, first_frame_only=False, rot=None):
                         ndpi,
                         ImageFormat.CCITTGroup4,
                         ccittdata,
+                        None,
                         imgwidthpx,
                         imgheightpx,
                         [],
@@ -1662,7 +1721,9 @@ def read_images(rawdata, colorspace, first_frame_only=False, rot=None):
                 color = Colorspace.L
         elif color in [
             Colorspace.RGB,
+            Colorspace.RGBA,
             Colorspace.L,
+            Colorspace.LA,
             Colorspace.CMYK,
             Colorspace["CMYK;I"],
             Colorspace.P,
@@ -1682,6 +1743,7 @@ def read_images(rawdata, colorspace, first_frame_only=False, rot=None):
                     ndpi,
                     imgformat,
                     imggz,
+                    None,
                     imgwidthpx,
                     imgheightpx,
                     [],
@@ -1692,27 +1754,42 @@ def read_images(rawdata, colorspace, first_frame_only=False, rot=None):
                 )
             )
         else:
-            # cheapo version to retrieve a PNG encoding of the payload is to
+            if (
-            # just save it with PIL. In the future this could be replaced by
+                color == Colorspace.RGBA
-            # dedicated function applying the Paeth PNG filter to the raw pixel
+                or color == Colorspace.LA
-            pngbuffer = BytesIO()
+                or "transparency" in newimg.info
-            newimg.save(pngbuffer, format="png")
+            ):
-            pngidat, palette = parse_png(pngbuffer.getvalue())
+                if color == Colorspace.RGBA:
-            # PIL does not provide the information about the original bits per
+                    newcolor = color
-            # sample. Thus, we retrieve that info manually by looking at byte 9 in
+                    r, g, b, a = newimg.split()
-            # the IHDR chunk. We know where to find that in the file because the
+                    newimg = Image.merge("RGB", (r, g, b))
-            # IHDR chunk must be the first chunk
+                elif color == Colorspace.LA:
-            pngbuffer.seek(24)
+                    newcolor = color
-            depth = ord(pngbuffer.read(1))
+                    l, a = newimg.split()
-            if depth not in [1, 2, 4, 8, 16]:
+                    newimg = l
-                raise ValueError("invalid bit depth: %d" % depth)
+                else:
+                    newcolor = Colorspace.RGBA
+                    r, g, b, a = newimg.convert(mode="RGBA").split()
+                    newimg = Image.merge("RGB", (r, g, b))
+
+                smaskidat, _, _ = to_png_data(a)
+                logger.warning(
+                    "Image contains an alpha channel which will be stored "
+                    "as a separate soft mask (/SMask) image in PDF."
+                )
+            else:
+                newcolor = color
+                smaskidat = None
+
+            pngidat, palette, depth = to_png_data(newimg)
             logger.debug("read_images() encoded an image as PNG")
             result.append(
                 (
-                    color,
+                    newcolor,
                     ndpi,
                     ImageFormat.PNG,
                     pngidat,
+                    smaskidat,
                     imgwidthpx,
                     imgheightpx,
                     palette,
@@ -1726,6 +1803,23 @@ def read_images(rawdata, colorspace, first_frame_only=False, rot=None):
     cleanup()
     return result
 
+def to_png_data(img):
+    # cheapo version to retrieve a PNG encoding of the payload is to
+    # just save it with PIL. In the future this could be replaced by
+    # dedicated function applying the Paeth PNG filter to the raw pixel
+    pngbuffer = BytesIO()
+    img.save(pngbuffer, format="png")
+
+    pngidat, palette = parse_png(pngbuffer.getvalue())
+    # PIL does not provide the information about the original bits per
+    # sample. Thus, we retrieve that info manually by looking at byte 9 in
+    # the IHDR chunk. We know where to find that in the file because the
+    # IHDR chunk must be the first chunk
+    pngbuffer.seek(24)
+    depth = ord(pngbuffer.read(1))
+    if depth not in [1, 2, 4, 8, 16]:
+        raise ValueError("invalid bit depth: %d" % depth)
+    return pngidat, palette, depth
 
 # converts a length in pixels to a length in PDF units (1/72 of an inch)
 def px_to_pt(length, dpi):
@@ -2118,6 +2212,7 @@ def convert(*images, **kwargs):
             ndpi,
             imgformat,
             imgdata,
+            smaskdata,
             imgwidthpx,
             imgheightpx,
             palette,
@@ -2171,6 +2266,7 @@ def convert(*images, **kwargs):
                 imgheightpx,
                 imgformat,
                 imgdata,
+                smaskdata,
                 imgwidthpdf,
                 imgheightpdf,
                 imgxpdf,

src/img2pdf_test.py

@@ -406,6 +406,23 @@ def compare_pdfimages_tiff(tmpdir, img, pdf):
 
 def compare_pdfimages_png(tmpdir, img, pdf, exact=True, icc=False):
     subprocess.check_call(["pdfimages", "-png", str(pdf), str(tmpdir / "images")])
+    # images-001.png is the grayscale SMask image (the original alpha channel)
+    if os.path.isfile(tmpdir / "images-001.png"):
+        subprocess.check_call(
+            [
+                "convert",
+                str(tmpdir / "images-000.png"),
+                str(tmpdir / "images-001.png"),
+                "-compose",
+                "copy-opacity",
+                "-composite",
+                str(tmpdir / "composite.png")
+            ]
+        )
+        (tmpdir / "images-000.png").unlink()
+        (tmpdir / "images-001.png").unlink()
+        os.rename(tmpdir / "composite.png", tmpdir / "images-000.png")
+
     if exact:
         if icc:
             raise Exception("not exact with icc")
@@ -2287,7 +2304,15 @@ def tiff_float_img(tmp_path_factory, tmp_normal_png):
 def tiff_cmyk8_img(tmp_path_factory, tmp_normal_png):
     in_img = tmp_path_factory.mktemp("tiff_cmyk8") / "in.tiff"
     subprocess.check_call(
-        ["convert", str(tmp_normal_png), "-colorspace", "cmyk", str(in_img)]
+        [
+            "convert",
+            str(tmp_normal_png),
+            "-colorspace",
+            "cmyk",
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
     )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
@@ -2344,6 +2369,8 @@ def tiff_cmyk16_img(tmp_path_factory, tmp_normal_png):
             "16",
             "-colorspace",
             "cmyk",
+            "-compress",
+            "Zip",
             str(in_img),
         ]
     )
@@ -2394,7 +2421,15 @@ def tiff_cmyk16_img(tmp_path_factory, tmp_normal_png):
 @pytest.fixture(scope="session")
 def tiff_rgb8_img(tmp_path_factory, tmp_normal_png):
     in_img = tmp_path_factory.mktemp("tiff_rgb8") / "in.tiff"
-    subprocess.check_call(["convert", str(tmp_normal_png), str(in_img)])
+    subprocess.check_call(
+        [
+            "convert",
+            str(tmp_normal_png),
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
+    )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
     # somewhere between imagemagick 6.9.7.4 and 6.9.9.34, the json output was
@@ -2442,7 +2477,15 @@ def tiff_rgb8_img(tmp_path_factory, tmp_normal_png):
 def tiff_rgb12_img(tmp_path_factory, tmp_normal16_png):
     in_img = tmp_path_factory.mktemp("tiff_rgb8") / "in.tiff"
     subprocess.check_call(
-        ["convert", str(tmp_normal16_png), "-depth", "12", str(in_img)]
+        [
+            "convert",
+            str(tmp_normal16_png),
+            "-depth",
+            "12",
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
     )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
@@ -2495,7 +2538,15 @@ def tiff_rgb12_img(tmp_path_factory, tmp_normal16_png):
 def tiff_rgb14_img(tmp_path_factory, tmp_normal16_png):
     in_img = tmp_path_factory.mktemp("tiff_rgb8") / "in.tiff"
     subprocess.check_call(
-        ["convert", str(tmp_normal16_png), "-depth", "14", str(in_img)]
+        [
+            "convert",
+            str(tmp_normal16_png),
+            "-depth",
+            "14",
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
     )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
@@ -2548,7 +2599,15 @@ def tiff_rgb14_img(tmp_path_factory, tmp_normal16_png):
 def tiff_rgb16_img(tmp_path_factory, tmp_normal16_png):
     in_img = tmp_path_factory.mktemp("tiff_rgb8") / "in.tiff"
     subprocess.check_call(
-        ["convert", str(tmp_normal16_png), "-depth", "16", str(in_img)]
+        [
+            "convert",
+            str(tmp_normal16_png),
+            "-depth",
+            "16",
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
     )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
@@ -2597,7 +2656,16 @@ def tiff_rgb16_img(tmp_path_factory, tmp_normal16_png):
 def tiff_rgba8_img(tmp_path_factory, tmp_alpha_png):
     in_img = tmp_path_factory.mktemp("tiff_rgba8") / "in.tiff"
     subprocess.check_call(
-        ["convert", str(tmp_alpha_png), "-depth", "8", "-strip", str(in_img)]
+        [
+            "convert",
+            str(tmp_alpha_png),
+            "-depth",
+            "8",
+            "-strip",
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
     )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
@@ -2646,7 +2714,16 @@ def tiff_rgba8_img(tmp_path_factory, tmp_alpha_png):
 def tiff_rgba16_img(tmp_path_factory, tmp_alpha_png):
     in_img = tmp_path_factory.mktemp("tiff_rgba16") / "in.tiff"
     subprocess.check_call(
-        ["convert", str(tmp_alpha_png), "-depth", "16", "-strip", str(in_img)]
+        [
+            "convert",
+            str(tmp_alpha_png),
+            "-depth",
+            "16",
+            "-strip",
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
     )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
@@ -2694,7 +2771,17 @@ def tiff_rgba16_img(tmp_path_factory, tmp_alpha_png):
 @pytest.fixture(scope="session")
 def tiff_gray1_img(tmp_path_factory, tmp_gray1_png):
     in_img = tmp_path_factory.mktemp("tiff_gray1") / "in.tiff"
-    subprocess.check_call(["convert", str(tmp_gray1_png), "-depth", "1", str(in_img)])
+    subprocess.check_call(
+        [
+            "convert",
+            str(tmp_gray1_png),
+            "-depth",
+            "1",
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
+    )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
     # somewhere between imagemagick 6.9.7.4 and 6.9.9.34, the json output was
@@ -2742,7 +2829,17 @@ def tiff_gray1_img(tmp_path_factory, tmp_gray1_png):
 @pytest.fixture(scope="session")
 def tiff_gray2_img(tmp_path_factory, tmp_gray2_png):
     in_img = tmp_path_factory.mktemp("tiff_gray2") / "in.tiff"
-    subprocess.check_call(["convert", str(tmp_gray2_png), "-depth", "2", str(in_img)])
+    subprocess.check_call(
+        [
+            "convert",
+            str(tmp_gray2_png),
+            "-depth",
+            "2",
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
+    )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
     # somewhere between imagemagick 6.9.7.4 and 6.9.9.34, the json output was
@@ -2790,7 +2887,17 @@ def tiff_gray2_img(tmp_path_factory, tmp_gray2_png):
 @pytest.fixture(scope="session")
 def tiff_gray4_img(tmp_path_factory, tmp_gray4_png):
     in_img = tmp_path_factory.mktemp("tiff_gray4") / "in.tiff"
-    subprocess.check_call(["convert", str(tmp_gray4_png), "-depth", "4", str(in_img)])
+    subprocess.check_call(
+        [
+            "convert",
+            str(tmp_gray4_png),
+            "-depth",
+            "4",
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
+    )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
     # somewhere between imagemagick 6.9.7.4 and 6.9.9.34, the json output was
@@ -2838,7 +2945,17 @@ def tiff_gray4_img(tmp_path_factory, tmp_gray4_png):
 @pytest.fixture(scope="session")
 def tiff_gray8_img(tmp_path_factory, tmp_gray8_png):
     in_img = tmp_path_factory.mktemp("tiff_gray8") / "in.tiff"
-    subprocess.check_call(["convert", str(tmp_gray8_png), "-depth", "8", str(in_img)])
+    subprocess.check_call(
+        [
+            "convert",
+            str(tmp_gray8_png),
+            "-depth",
+            "8",
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
+    )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
     # somewhere between imagemagick 6.9.7.4 and 6.9.9.34, the json output was
@@ -2886,7 +3003,17 @@ def tiff_gray8_img(tmp_path_factory, tmp_gray8_png):
 @pytest.fixture(scope="session")
 def tiff_gray16_img(tmp_path_factory, tmp_gray16_png):
     in_img = tmp_path_factory.mktemp("tiff_gray16") / "in.tiff"
-    subprocess.check_call(["convert", str(tmp_gray16_png), "-depth", "16", str(in_img)])
+    subprocess.check_call(
+        [
+            "convert",
+            str(tmp_gray16_png),
+            "-depth",
+            "16",
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
+    )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
     # somewhere between imagemagick 6.9.7.4 and 6.9.9.34, the json output was
@@ -2935,7 +3062,15 @@ def tiff_gray16_img(tmp_path_factory, tmp_gray16_png):
 def tiff_multipage_img(tmp_path_factory, tmp_normal_png, tmp_inverse_png):
     in_img = tmp_path_factory.mktemp("tiff_multipage_img") / "in.tiff"
     subprocess.check_call(
-        ["convert", str(tmp_normal_png), str(tmp_inverse_png), "-strip", str(in_img)]
+        [
+            "convert",
+            str(tmp_normal_png),
+            str(tmp_inverse_png),
+            "-strip",
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
     )
     identify = json.loads(
         subprocess.check_output(["convert", str(in_img) + "[0]", "json:"])
@@ -3027,7 +3162,15 @@ def tiff_multipage_img(tmp_path_factory, tmp_normal_png, tmp_inverse_png):
 @pytest.fixture(scope="session")
 def tiff_palette1_img(tmp_path_factory, tmp_palette1_png):
     in_img = tmp_path_factory.mktemp("tiff_palette1_img") / "in.tiff"
-    subprocess.check_call(["convert", str(tmp_palette1_png), str(in_img)])
+    subprocess.check_call(
+        [
+            "convert",
+            str(tmp_palette1_png),
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
+    )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
     # somewhere between imagemagick 6.9.7.4 and 6.9.9.34, the json output was
@@ -3076,7 +3219,15 @@ def tiff_palette1_img(tmp_path_factory, tmp_palette1_png):
 @pytest.fixture(scope="session")
 def tiff_palette2_img(tmp_path_factory, tmp_palette2_png):
     in_img = tmp_path_factory.mktemp("tiff_palette2_img") / "in.tiff"
-    subprocess.check_call(["convert", str(tmp_palette2_png), str(in_img)])
+    subprocess.check_call(
+        [
+            "convert",
+            str(tmp_palette2_png),
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
+    )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
     # somewhere between imagemagick 6.9.7.4 and 6.9.9.34, the json output was
@@ -3125,7 +3276,15 @@ def tiff_palette2_img(tmp_path_factory, tmp_palette2_png):
 @pytest.fixture(scope="session")
 def tiff_palette4_img(tmp_path_factory, tmp_palette4_png):
     in_img = tmp_path_factory.mktemp("tiff_palette4_img") / "in.tiff"
-    subprocess.check_call(["convert", str(tmp_palette4_png), str(in_img)])
+    subprocess.check_call(
+        [
+            "convert",
+            str(tmp_palette4_png),
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
+    )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
     # somewhere between imagemagick 6.9.7.4 and 6.9.9.34, the json output was
@@ -3174,7 +3333,15 @@ def tiff_palette4_img(tmp_path_factory, tmp_palette4_png):
 @pytest.fixture(scope="session")
 def tiff_palette8_img(tmp_path_factory, tmp_palette8_png):
     in_img = tmp_path_factory.mktemp("tiff_palette8_img") / "in.tiff"
-    subprocess.check_call(["convert", str(tmp_palette8_png), str(in_img)])
+    subprocess.check_call(
+        [
+            "convert",
+            str(tmp_palette8_png),
+            "-compress",
+            "Zip",
+            str(in_img)
+        ]
+    )
     identify = json.loads(subprocess.check_output(["convert", str(in_img), "json:"]))
     assert len(identify) == 1
     # somewhere between imagemagick 6.9.7.4 and 6.9.9.34, the json output was
@@ -3234,6 +3401,8 @@ def tiff_ccitt_lsb_m2l_white_img(tmp_path_factory, tmp_gray1_png):
             "tiff:fill-order=msb",
             "-define",
             "quantum:polarity=min-is-white",
+            "-compress",
+            "Group4",
             str(in_img),
         ]
     )
@@ -3313,6 +3482,8 @@ def tiff_ccitt_msb_m2l_white_img(tmp_path_factory, tmp_gray1_png):
             "tiff:fill-order=msb",
             "-define",
             "quantum:polarity=min-is-white",
+            "-compress",
+            "Group4",
             str(in_img),
         ]
     )
@@ -3393,6 +3564,8 @@ def tiff_ccitt_msb_l2m_white_img(tmp_path_factory, tmp_gray1_png):
             "tiff:fill-order=lsb",
             "-define",
             "quantum:polarity=min-is-white",
+            "-compress",
+            "Group4",
             str(in_img),
         ]
     )
@@ -3478,6 +3651,8 @@ def tiff_ccitt_lsb_m2l_black_img(tmp_path_factory, tmp_gray1_png):
             "tiff:fill-order=msb",
             "-define",
             "quantum:polarity=min-is-black",
+            "-compress",
+            "Group4",
             str(in_img),
         ]
     )
@@ -3557,6 +3732,8 @@ def tiff_ccitt_nometa1_img(tmp_path_factory, tmp_gray1_png):
             "tiff:fill-order=msb",
             "-define",
             "quantum:polarity=min-is-white",
+            "-compress",
+            "Group4",
             str(in_img),
         ]
     )
@@ -3645,6 +3822,8 @@ def tiff_ccitt_nometa2_img(tmp_path_factory, tmp_gray1_png):
             "tiff:fill-order=msb",
             "-define",
             "quantum:polarity=min-is-white",
+            "-compress",
+            "Group4",
             str(in_img),
         ]
     )
@@ -3904,6 +4083,86 @@ def png_rgb8_pdf(tmp_path_factory, png_rgb8_img, request):
     out_pdf.unlink()
 
 
+@pytest.fixture(scope="session", params=["internal", "pikepdf", "pdfrw"])
+def png_rgba8_pdf(tmp_path_factory, png_rgba8_img, request):
+    out_pdf = tmp_path_factory.mktemp("png_rgba8_pdf") / "out.pdf"
+    subprocess.check_call(
+        [
+            "src/img2pdf.py",
+            "--producer=",
+            "--nodate",
+            "--engine=" + request.param,
+            "--output=" + str(out_pdf),
+            str(png_rgba8_img),
+        ]
+    )
+    with pikepdf.open(str(out_pdf)) as p:
+        assert (
+            p.pages[0].Contents.read_bytes()
+            == b"q\n45.0000 0 0 45.0000 0.0000 0.0000 cm\n/Im0 Do\nQ"
+        )
+        assert p.pages[0].Resources.XObject.Im0.BitsPerComponent == 8
+        assert p.pages[0].Resources.XObject.Im0.ColorSpace == "/DeviceRGB"
+        assert p.pages[0].Resources.XObject.Im0.DecodeParms.BitsPerComponent == 8
+        assert p.pages[0].Resources.XObject.Im0.DecodeParms.Colors == 3
+        assert p.pages[0].Resources.XObject.Im0.DecodeParms.Predictor == 15
+        assert p.pages[0].Resources.XObject.Im0.Filter == "/FlateDecode"
+        assert p.pages[0].Resources.XObject.Im0.Height == 60
+        assert p.pages[0].Resources.XObject.Im0.Width == 60
+        assert p.pages[0].Resources.XObject.Im0.SMask is not None
+
+        assert p.pages[0].Resources.XObject.Im0.SMask.BitsPerComponent == 8
+        assert p.pages[0].Resources.XObject.Im0.SMask.ColorSpace == "/DeviceGray"
+        assert p.pages[0].Resources.XObject.Im0.SMask.DecodeParms.BitsPerComponent == 8
+        assert p.pages[0].Resources.XObject.Im0.SMask.DecodeParms.Colors == 1
+        assert p.pages[0].Resources.XObject.Im0.SMask.DecodeParms.Predictor == 15
+        assert p.pages[0].Resources.XObject.Im0.SMask.Filter == "/FlateDecode"
+        assert p.pages[0].Resources.XObject.Im0.SMask.Height == 60
+        assert p.pages[0].Resources.XObject.Im0.SMask.Width == 60
+    yield out_pdf
+    out_pdf.unlink()
+
+
+@pytest.fixture(scope="session", params=["internal", "pikepdf", "pdfrw"])
+def gif_transparent_pdf(tmp_path_factory, gif_transparent_img, request):
+    out_pdf = tmp_path_factory.mktemp("gif_transparent_pdf") / "out.pdf"
+    subprocess.check_call(
+        [
+            "src/img2pdf.py",
+            "--producer=",
+            "--nodate",
+            "--engine=" + request.param,
+            "--output=" + str(out_pdf),
+            str(gif_transparent_img),
+        ]
+    )
+    with pikepdf.open(str(out_pdf)) as p:
+        assert (
+            p.pages[0].Contents.read_bytes()
+            == b"q\n45.0000 0 0 45.0000 0.0000 0.0000 cm\n/Im0 Do\nQ"
+        )
+        assert p.pages[0].Resources.XObject.Im0.BitsPerComponent == 8
+        assert p.pages[0].Resources.XObject.Im0.ColorSpace == "/DeviceRGB"
+        assert p.pages[0].Resources.XObject.Im0.DecodeParms.BitsPerComponent == 8
+        assert p.pages[0].Resources.XObject.Im0.DecodeParms.Colors == 3
+        assert p.pages[0].Resources.XObject.Im0.DecodeParms.Predictor == 15
+        assert p.pages[0].Resources.XObject.Im0.Filter == "/FlateDecode"
+        assert p.pages[0].Resources.XObject.Im0.Height == 60
+        assert p.pages[0].Resources.XObject.Im0.Width == 60
+        assert p.pages[0].Resources.XObject.Im0.SMask is not None
+
+        assert p.pages[0].Resources.XObject.Im0.SMask.BitsPerComponent == 8
+        assert p.pages[0].Resources.XObject.Im0.SMask.ColorSpace == "/DeviceGray"
+        assert p.pages[0].Resources.XObject.Im0.SMask.DecodeParms.BitsPerComponent == 8
+        assert p.pages[0].Resources.XObject.Im0.SMask.DecodeParms.Colors == 1
+        assert p.pages[0].Resources.XObject.Im0.SMask.DecodeParms.Predictor == 15
+        assert p.pages[0].Resources.XObject.Im0.SMask.Filter == "/FlateDecode"
+        assert p.pages[0].Resources.XObject.Im0.SMask.Height == 60
+        assert p.pages[0].Resources.XObject.Im0.SMask.Width == 60
+    yield out_pdf
+    out_pdf.unlink()
+
+
 @pytest.fixture(scope="session", params=["internal", "pikepdf", "pdfrw"])
 def png_rgb16_pdf(tmp_path_factory, png_rgb16_img, request):
     out_pdf = tmp_path_factory.mktemp("png_rgb16_pdf") / "out.pdf"
@@ -4084,6 +4343,46 @@ def png_gray8_pdf(tmp_path_factory, tmp_gray8_png, request):
     out_pdf.unlink()
 
 
+@pytest.fixture(scope="session", params=["internal", "pikepdf", "pdfrw"])
+def png_gray8a_pdf(tmp_path_factory, png_gray8a_img, request):
+    out_pdf = tmp_path_factory.mktemp("png_gray8a_pdf") / "out.pdf"
+    subprocess.check_call(
+        [
+            "src/img2pdf.py",
+            "--producer=",
+            "--nodate",
+            "--engine=" + request.param,
+            "--output=" + str(out_pdf),
+            str(png_gray8a_img),
+        ]
+    )
+    with pikepdf.open(str(out_pdf)) as p:
+        assert (
+            p.pages[0].Contents.read_bytes()
+            == b"q\n45.0000 0 0 45.0000 0.0000 0.0000 cm\n/Im0 Do\nQ"
+        )
+        assert p.pages[0].Resources.XObject.Im0.BitsPerComponent == 8
+        assert p.pages[0].Resources.XObject.Im0.ColorSpace == "/DeviceGray"
+        assert p.pages[0].Resources.XObject.Im0.DecodeParms.BitsPerComponent == 8
+        assert p.pages[0].Resources.XObject.Im0.DecodeParms.Colors == 1
+        assert p.pages[0].Resources.XObject.Im0.DecodeParms.Predictor == 15
+        assert p.pages[0].Resources.XObject.Im0.Filter == "/FlateDecode"
+        assert p.pages[0].Resources.XObject.Im0.Height == 60
+        assert p.pages[0].Resources.XObject.Im0.Width == 60
+        assert p.pages[0].Resources.XObject.Im0.SMask is not None
+
+        assert p.pages[0].Resources.XObject.Im0.SMask.BitsPerComponent == 8
+        assert p.pages[0].Resources.XObject.Im0.SMask.ColorSpace == "/DeviceGray"
+        assert p.pages[0].Resources.XObject.Im0.SMask.DecodeParms.BitsPerComponent == 8
+        assert p.pages[0].Resources.XObject.Im0.SMask.DecodeParms.Colors == 1
+        assert p.pages[0].Resources.XObject.Im0.SMask.DecodeParms.Predictor == 15
+        assert p.pages[0].Resources.XObject.Im0.SMask.Filter == "/FlateDecode"
+        assert p.pages[0].Resources.XObject.Im0.SMask.Height == 60
+        assert p.pages[0].Resources.XObject.Im0.SMask.Width == 60
+    yield out_pdf
+    out_pdf.unlink()
+
+
 @pytest.fixture(scope="session", params=["internal", "pikepdf", "pdfrw"])
 def png_gray16_pdf(tmp_path_factory, tmp_gray16_png, request):
     out_pdf = tmp_path_factory.mktemp("png_gray16_pdf") / "out.pdf"
@@ -5048,7 +5347,7 @@ def test_jpg_cmyk(tmp_path_factory, jpg_cmyk_img, jpg_cmyk_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 @pytest.mark.skipif(
@@ -5063,7 +5362,7 @@ def test_jpg_2000(tmp_path_factory, jpg_2000_img, jpg_2000_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_png_rgb8(tmp_path_factory, png_rgb8_img, png_rgb8_pdf):
@@ -5075,7 +5374,7 @@ def test_png_rgb8(tmp_path_factory, png_rgb8_img, png_rgb8_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_png_rgb16(tmp_path_factory, png_rgb16_img, png_rgb16_pdf):
@@ -5087,30 +5386,15 @@ def test_png_rgb16(tmp_path_factory, png_rgb16_img, png_rgb16_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
-@pytest.mark.parametrize("engine", ["internal", "pikepdf", "pdfrw"])
+def test_png_rgba8(tmp_path_factory, png_rgba8_img, png_rgba8_pdf):
-def test_png_rgba8(tmp_path_factory, png_rgba8_img, engine):
+    tmpdir = tmp_path_factory.mktemp("png_rgba8")
-    out_pdf = tmp_path_factory.mktemp("png_rgba8") / "out.pdf"
+    compare_pdfimages_png(tmpdir, png_rgba8_img, png_rgba8_pdf)
-    assert (
-        0
-        != subprocess.run(
-            [
-                "src/img2pdf.py",
-                "--producer=",
-                "--nodate",
-                "--engine=" + engine,
-                "--output=" + str(out_pdf),
-                str(png_rgba8_img),
-            ]
-        ).returncode
-    )
-    out_pdf.unlink()
-
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 @pytest.mark.parametrize("engine", ["internal", "pikepdf", "pdfrw"])
@@ -5133,30 +5417,16 @@ def test_png_rgba16(tmp_path_factory, png_rgba16_img, engine):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
-@pytest.mark.parametrize("engine", ["internal", "pikepdf", "pdfrw"])
+def test_png_gray8a(tmp_path_factory, png_gray8a_img, png_gray8a_pdf):
-def test_png_gray8a(tmp_path_factory, png_gray8a_img, engine):
+    tmpdir = tmp_path_factory.mktemp("png_gray8a")
-    out_pdf = tmp_path_factory.mktemp("png_gray8a") / "out.pdf"
+    compare_pdfimages_png(tmpdir, png_gray8a_img, png_gray8a_pdf)
-    assert (
-        0
-        != subprocess.run(
-            [
-                "src/img2pdf.py",
-                "--producer=",
-                "--nodate",
-                "--engine=" + engine,
-                "--output=" + str(out_pdf),
-                str(png_gray8a_img),
-            ]
-        ).returncode
-    )
-    out_pdf.unlink()
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 @pytest.mark.parametrize("engine", ["internal", "pikepdf", "pdfrw"])
@@ -5179,7 +5449,7 @@ def test_png_gray16a(tmp_path_factory, png_gray16a_img, engine):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_png_interlaced(tmp_path_factory, png_interlaced_img, png_interlaced_pdf):
@@ -5191,7 +5461,7 @@ def test_png_interlaced(tmp_path_factory, png_interlaced_img, png_interlaced_pdf
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_png_gray1(tmp_path_factory, png_gray1_img, png_gray1_pdf):
@@ -5203,7 +5473,7 @@ def test_png_gray1(tmp_path_factory, png_gray1_img, png_gray1_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_png_gray2(tmp_path_factory, png_gray2_img, png_gray2_pdf):
@@ -5215,7 +5485,7 @@ def test_png_gray2(tmp_path_factory, png_gray2_img, png_gray2_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_png_gray4(tmp_path_factory, png_gray4_img, png_gray4_pdf):
@@ -5227,7 +5497,7 @@ def test_png_gray4(tmp_path_factory, png_gray4_img, png_gray4_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_png_gray8(tmp_path_factory, png_gray8_img, png_gray8_pdf):
@@ -5239,7 +5509,7 @@ def test_png_gray8(tmp_path_factory, png_gray8_img, png_gray8_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_png_gray16(tmp_path_factory, png_gray16_img, png_gray16_pdf):
@@ -5255,7 +5525,7 @@ def test_png_gray16(tmp_path_factory, png_gray16_img, png_gray16_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_png_palette1(tmp_path_factory, png_palette1_img, png_palette1_pdf):
@@ -5267,7 +5537,7 @@ def test_png_palette1(tmp_path_factory, png_palette1_img, png_palette1_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_png_palette2(tmp_path_factory, png_palette2_img, png_palette2_pdf):
@@ -5279,7 +5549,7 @@ def test_png_palette2(tmp_path_factory, png_palette2_img, png_palette2_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_png_palette4(tmp_path_factory, png_palette4_img, png_palette4_pdf):
@@ -5291,7 +5561,7 @@ def test_png_palette4(tmp_path_factory, png_palette4_img, png_palette4_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_png_palette8(tmp_path_factory, png_palette8_img, png_palette8_pdf):
@@ -5315,30 +5585,16 @@ def test_png_icc(tmp_path_factory, png_icc_img, png_icc_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
-@pytest.mark.parametrize("engine", ["internal", "pikepdf", "pdfrw"])
+def test_gif_transparent(tmp_path_factory, gif_transparent_img, gif_transparent_pdf):
-def test_gif_transparent(tmp_path_factory, gif_transparent_img, engine):
+    tmpdir = tmp_path_factory.mktemp("gif_transparent")
-    out_pdf = tmp_path_factory.mktemp("gif_transparent") / "out.pdf"
+    compare_pdfimages_png(tmpdir, gif_transparent_img, gif_transparent_pdf)
-    assert (
-        0
-        != subprocess.run(
-            [
-                "src/img2pdf.py",
-                "--producer=",
-                "--nodate",
-                "--engine=" + engine,
-                "--output=" + str(out_pdf),
-                str(gif_transparent_img),
-            ]
-        ).returncode
-    )
-    out_pdf.unlink()
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_gif_palette1(tmp_path_factory, gif_palette1_img, gif_palette1_pdf):
@@ -5350,7 +5606,7 @@ def test_gif_palette1(tmp_path_factory, gif_palette1_img, gif_palette1_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_gif_palette2(tmp_path_factory, gif_palette2_img, gif_palette2_pdf):
@@ -5362,7 +5618,7 @@ def test_gif_palette2(tmp_path_factory, gif_palette2_img, gif_palette2_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_gif_palette4(tmp_path_factory, gif_palette4_img, gif_palette4_pdf):
@@ -5374,7 +5630,7 @@ def test_gif_palette4(tmp_path_factory, gif_palette4_img, gif_palette4_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_gif_palette8(tmp_path_factory, gif_palette8_img, gif_palette8_pdf):
@@ -5386,7 +5642,7 @@ def test_gif_palette8(tmp_path_factory, gif_palette8_img, gif_palette8_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_gif_animation(tmp_path_factory, gif_animation_img, gif_animation_pdf):
@@ -5433,7 +5689,7 @@ def test_tiff_float(tmp_path_factory, tiff_float_img, engine):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_cmyk8(tmp_path_factory, tiff_cmyk8_img, tiff_cmyk8_pdf):
@@ -5447,7 +5703,7 @@ def test_tiff_cmyk8(tmp_path_factory, tiff_cmyk8_img, tiff_cmyk8_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 @pytest.mark.parametrize("engine", ["internal", "pikepdf", "pdfrw"])
@@ -5471,7 +5727,7 @@ def test_tiff_cmyk16(tmp_path_factory, tiff_cmyk16_img, engine):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_rgb8(tmp_path_factory, tiff_rgb8_img, tiff_rgb8_pdf):
@@ -5483,7 +5739,7 @@ def test_tiff_rgb8(tmp_path_factory, tiff_rgb8_img, tiff_rgb8_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 @pytest.mark.parametrize("engine", ["internal", "pikepdf", "pdfrw"])
@@ -5507,7 +5763,7 @@ def test_tiff_rgb12(tmp_path_factory, tiff_rgb12_img, engine):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 @pytest.mark.parametrize("engine", ["internal", "pikepdf", "pdfrw"])
@@ -5531,7 +5787,7 @@ def test_tiff_rgb14(tmp_path_factory, tiff_rgb14_img, engine):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 @pytest.mark.parametrize("engine", ["internal", "pikepdf", "pdfrw"])
@@ -5555,7 +5811,7 @@ def test_tiff_rgb16(tmp_path_factory, tiff_rgb16_img, engine):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 @pytest.mark.parametrize("engine", ["internal", "pikepdf", "pdfrw"])
@@ -5578,7 +5834,7 @@ def test_tiff_rgba8(tmp_path_factory, tiff_rgba8_img, engine):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 @pytest.mark.parametrize("engine", ["internal", "pikepdf", "pdfrw"])
@@ -5601,7 +5857,7 @@ def test_tiff_rgba16(tmp_path_factory, tiff_rgba16_img, engine):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_gray1(tmp_path_factory, tiff_gray1_img, tiff_gray1_pdf):
@@ -5613,7 +5869,7 @@ def test_tiff_gray1(tmp_path_factory, tiff_gray1_img, tiff_gray1_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_gray2(tmp_path_factory, tiff_gray2_img, tiff_gray2_pdf):
@@ -5625,7 +5881,7 @@ def test_tiff_gray2(tmp_path_factory, tiff_gray2_img, tiff_gray2_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_gray4(tmp_path_factory, tiff_gray4_img, tiff_gray4_pdf):
@@ -5637,7 +5893,7 @@ def test_tiff_gray4(tmp_path_factory, tiff_gray4_img, tiff_gray4_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_gray8(tmp_path_factory, tiff_gray8_img, tiff_gray8_pdf):
@@ -5649,7 +5905,7 @@ def test_tiff_gray8(tmp_path_factory, tiff_gray8_img, tiff_gray8_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 @pytest.mark.parametrize("engine", ["internal", "pikepdf", "pdfrw"])
@@ -5672,7 +5928,7 @@ def test_tiff_gray16(tmp_path_factory, tiff_gray16_img, engine):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_multipage(tmp_path_factory, tiff_multipage_img, tiff_multipage_pdf):
@@ -5702,7 +5958,7 @@ def test_tiff_multipage(tmp_path_factory, tiff_multipage_img, tiff_multipage_pdf
     reason="requires imagemagick with support for keeping the palette depth",
 )
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_palette1(tmp_path_factory, tiff_palette1_img, tiff_palette1_pdf):
@@ -5718,7 +5974,7 @@ def test_tiff_palette1(tmp_path_factory, tiff_palette1_img, tiff_palette1_pdf):
     reason="requires imagemagick with support for keeping the palette depth",
 )
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_palette2(tmp_path_factory, tiff_palette2_img, tiff_palette2_pdf):
@@ -5734,7 +5990,7 @@ def test_tiff_palette2(tmp_path_factory, tiff_palette2_img, tiff_palette2_pdf):
     reason="requires imagemagick with support for keeping the palette depth",
 )
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_palette4(tmp_path_factory, tiff_palette4_img, tiff_palette4_pdf):
@@ -5746,7 +6002,7 @@ def test_tiff_palette4(tmp_path_factory, tiff_palette4_img, tiff_palette4_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_palette8(tmp_path_factory, tiff_palette8_img, tiff_palette8_pdf):
@@ -5758,7 +6014,7 @@ def test_tiff_palette8(tmp_path_factory, tiff_palette8_img, tiff_palette8_pdf):
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_ccitt_lsb_m2l_white(
@@ -5779,7 +6035,7 @@ def test_tiff_ccitt_lsb_m2l_white(
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_ccitt_msb_m2l_white(
@@ -5800,7 +6056,7 @@ def test_tiff_ccitt_msb_m2l_white(
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_ccitt_msb_l2m_white(
@@ -5825,7 +6081,7 @@ def test_tiff_ccitt_msb_l2m_white(
     reason="requires imagemagick with support for min-is-black",
 )
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_ccitt_lsb_m2l_black(
@@ -5846,7 +6102,7 @@ def test_tiff_ccitt_lsb_m2l_black(
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_ccitt_nometa1(
@@ -5862,7 +6118,7 @@ def test_tiff_ccitt_nometa1(
 
 
 @pytest.mark.skipif(
-    sys.platform in ["darwin", "win32"],
+    sys.platform in ["win32"],
     reason="test utilities not available on Windows and MacOS",
 )
 def test_tiff_ccitt_nometa2(