From 0d90ec67681f1236c058823db4a8154a89866561 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Tam=C3=A1s=20Zahola?= Date: Sat, 19 Jun 2021 01:19:06 +0200 Subject: [PATCH] Use PNG predictor for /SMask too --- src/img2pdf.py | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/src/img2pdf.py b/src/img2pdf.py index 467527c..64bdd57 100755 --- a/src/img2pdf.py +++ b/src/img2pdf.py @@ -885,6 +885,13 @@ class pdfdoc(object): 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 @@ -1752,11 +1759,11 @@ def read_images(rawdata, colorspace, first_frame_only=False, rot=None): r, g, b, a = newimg.convert(mode="RGBA").split() newimg = Image.merge("RGB", (r, g, b)) - smaskdata = zlib.compress(a.tobytes()) + 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 - smaskdata = None + smaskidat = None pngidat, palette, depth = to_png_data(newimg) logger.debug("read_images() encoded an image as PNG") @@ -1766,7 +1773,7 @@ def read_images(rawdata, colorspace, first_frame_only=False, rot=None): ndpi, ImageFormat.PNG, pngidat, - smaskdata, + smaskidat, imgwidthpx, imgheightpx, palette,