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@ -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)
# 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
depth = rawdata[24]
if depth not in [1, 2, 4, 8, 16]:
raise ValueError("invalid bit depth: %d" % depth)
logger.debug("read_images() embeds a PNG")
cleanup()
return [
(
color,
ndpi,
imgformat,
pngidat,
imgwidthpx,
imgheightpx,
palette,
False,
depth,
rotation,
iccp,
)
]
if (
color != Colorspace.RGBA
and color != Colorspace.LA
and "transparency" not in imgdata.info
):
pngidat, palette = parse_png(rawdata)
# 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
depth = rawdata[24]
if depth not in [1, 2, 4, 8, 16]:
raise ValueError("invalid bit depth: %d" % depth)
logger.debug("read_images() embeds a PNG")
cleanup()
return [
(
color,
ndpi,
imgformat,
pngidat,
None,
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
# 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()
newimg.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)
if (
color == Colorspace.RGBA
or color == Colorspace.LA
or "transparency" in newimg.info
):
if color == Colorspace.RGBA:
newcolor = color
r, g, b, a = newimg.split()
newimg = Image.merge("RGB", (r, g, b))
elif color == Colorspace.LA:
newcolor = color
l, a = newimg.split()
newimg = l
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,

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