Change default rendering for pdf thumbnails to png
Now if you have [GFX][thumbnails_png] = 0, the default value, pdf thumbnails are converted to gif.
If you set it to [GFX][thumbnails_png] = 1, pdf thumbnails are converted to png.
PDF used as images on FE are renderd via this chain, resulting in 256 color gifs on a page.
Add new config value for pdf2img conversion, like this:
[GFX][pdf2imgformat] = 'jpg'
[GFX][pdf2imgformat] = 'png'
[GFX][pdf2imgformat] = 'gif'
default should be jpg.
Updated by Stephan Bauer 10 months ago
I'm showing bigger images converted from pdf files in the frontend.
These images would be best shown as jpg not as gif or png.
Here is a comparison between the different file formats TYPO3 created.
The files are 600x425px.
The png file is not optimized in any way. With an optimizer I could reduce the size to 325kb which is sill to much.
I could produce jpg file after changing $targetFileExtension to 'jpg' in file /sysext/core/Classes/Resource/Processing/AbstractGraphicalTask.php in line 81.
I think that the option 'thumbnails_png' should be deprecated and there should be an option where we can choose a file format even new formats like webp.
One problem I found after changing $targetFileExtension to 'jpg' is that some of these PDF files are converted to gif oder png with transparency and the jpg file shows a black frame because the color for transparency is set to this.