josch/img2pdf
3
6
Fork 10
Code Issues 21 Pull requests 5 Projects Releases 3 Wiki Activity

clarify that input with an alpha channel requires additional computation (closes: #142)

Browse source
This commit is contained in:
Johannes Schauer Marin Rodrigues 2022-04-07 17:13:16 +02:00
parent e8ca53738f
commit 3b117e674b
Signed by: josch
GPG key ID: F2CBA5C78FBD83E1
2 changed files with 11 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

18
README.md
View file

@ -27,15 +27,15 @@ software, because the raw pixel data never has to be loaded into memory.
The following table shows how img2pdf handles different input depending on the
input file format and image color space.
| Format | Colorspace | Result |
| -------------------- | ------------------------------ | ------------- |
| JPEG | any | direct |
| JPEG2000 | any | direct |
| PNG (non-interlaced) | any | direct |
| TIFF (CCITT Group 4) | monochrome | direct |
| any | any except CMYK and monochrome | PNG Paeth |
| any | monochrome | CCITT Group 4 |
| any | CMYK | flate |
| Format | Colorspace | Result |
| ------------------------------------- | ------------------------------ | ------------- |
| JPEG | any | direct |
| JPEG2000 | any | direct |
| PNG (non-interlaced, no transparency) | any | direct |
| TIFF (CCITT Group 4) | monochrome | direct |
| any | any except CMYK and monochrome | PNG Paeth |
| any | monochrome | CCITT Group 4 |
| any | CMYK | flate |
For JPEG, JPEG2000, non-interlaced PNG and TIFF images with CCITT Group 4
encoded data, img2pdf directly embeds the image data into the PDF without

4
src/img2pdf.py
View file

@ -1823,8 +1823,8 @@ def read_images(rawdata, colorspace, first_frame_only=False, rot=None):
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."
"Image contains an alpha channel. Computing a separate "
"soft mask (/SMask) image to store transparency in PDF."
)
elif color in [Colorspace.P, Colorspace.PA] and iccp is not None:
# PDF does not support palette images with icc profile