Am 26.05.2011 18:17, schrieb Peter Rolf:
Am 26.05.2011 12:52, schrieb Peter Rolf:
Am 25.05.2011 21:54, schrieb Hartmut Henkel: [..]
no. There is a "PNG Copy" function for literal embedding of the PNG file, but that triggers only, if the file simultaneously satisfies quite a few conditions, which are about: non-interlaced, no palette, no transparency, no gamma coming with it, no gamma modification requested, no white adjustment in the PNG, and a few more rare others. Else it's de-compressed and then re-compressed to the \pdfcompresslevel, and additional streams and dicts are added. You see in the log if it finally was "PNG Copy" or not.
[..]
These are about the factors affecting the PNG to PDF size. For your big PNG graphic you may find a preprocessing (e. g., pngtopnm | pnmtopng will definitely remove all fat) that makes it compliant with the "PNG copy".
I will give that a try. But I doubt that there is much 'fat' on that graphic. Anyhow, you never know before you have tried it. :-)
No luck. I used imagemagick to convert to pnm and back. Transparency was removed before by adding a white background, also all not critical chunks (ICC profile, backgroundcolor, resolution, creation and modify date, comment) were removed. The graphic is a valid PNG (TweakPNG) and aside from the size, there is nothing special with this graphic. Still no '(PNG copy)'.
@luigi: an ICC profile definitely breaks the <png copy> rules
The only chunks left are
IHDR PNG image header: 5900x4094, 8bits/sample, truecolor, noninterlaced IDAT PNG image data .. IDAT PNG image data IEND end-of-image marker
Mh, where is the show stopper? The compression method?
Looks like some of ConTeXt PDF/X-related settings is causing this. If I reduce the code to the pure picture, the '(PNG copy)' is triggered. Probably the active color management (default color space) is breaking the copy process here. Sorry for any inconvenience. I should have tested this case before... Best wishes, Peter
Regards, Peter ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki!
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