Comparison with econvert (ExactImage) #143

Closed
opened 2 years ago by mara0004 · 3 comments

Hi,

I'd be curious to know how img2pdf performs compared to econvert from ExactImage, which is some kind of image processing library that aims to be a faster alternative to ImageMagick. You can use it like this:

econvert -i some_image.jpg -o econvert_output.pdf

The corresponding Debian packages are called exactimage and python3-exactimage for the Python bindings.

Thanks!

Hi, I'd be curious to know how img2pdf performs compared to `econvert` from [ExactImage](http://www.exactcode.com/opensource/exactimage/), which is some kind of image processing library that aims to be a faster alternative to ImageMagick. You can use it like this: ```bash econvert -i some_image.jpg -o econvert_output.pdf ``` The corresponding Debian packages are called `exactimage` and `python3-exactimage` for the Python bindings. Thanks!
josch commented 2 years ago
Owner

Like pdflatex and podofoimg2pf it seems that econvert is able to embed JPEG images into PDF directly without re-encoding but when given other file formats stores them just using flate compressen, which unnecessarily increases the filesize. Furthermore, it throws an error with CMYK TIF input:

TIFCodec: Unrecognized photometric: 5
Error reading input file src/tests/input/CMYK.tif, image: 0
Error: 1 filename(s) left for writing

It also doesn't store CMYK jpeg files as CMYK but converts them to RGB, so it's not lossless. When trying to feed it 16bit files, it errors out with Unhandled bps/spp combination. It also seems to choose JPEG encoding when using it on some file types (like palette images) making it again not lossless.

Like pdflatex and podofoimg2pf it seems that econvert is able to embed JPEG images into PDF directly without re-encoding but when given other file formats stores them just using flate compressen, which unnecessarily increases the filesize. Furthermore, it throws an error with CMYK TIF input: ``` TIFCodec: Unrecognized photometric: 5 Error reading input file src/tests/input/CMYK.tif, image: 0 Error: 1 filename(s) left for writing ``` It also doesn't store CMYK jpeg files as CMYK but converts them to RGB, so it's not lossless. When trying to feed it 16bit files, it errors out with `Unhandled bps/spp combination`. It also seems to choose JPEG encoding when using it on some file types (like palette images) making it again not lossless.
Poster

Thanks!

Thanks!
mara0004 closed this issue 2 years ago
josch commented 2 years ago
Owner

Reopening so that I can close this with a commit.

Reopening so that I can close this with a commit.
josch reopened this issue 2 years ago
josch closed this issue 2 years ago
Sign in to join this conversation.
No Milestone
No project
No Assignees
2 Participants
Notifications
Due Date
The due date is invalid or out of range. Please use the format 'yyyy-mm-dd'.

No due date set.

Dependencies

No dependencies set.

Reference: josch/img2pdf#143
Loading…
There is no content yet.