PNG export resolution problem

[Michael Baudino]

Hello,

While scanning any document (I use 150dpi for scanning, but the bug happens whichever scan resolution you use) and saving it as a PNG file, simple-scan sets incorrect resolution in PNG file headers. I noticed it when a friend trying to open it in Photoshop mentionned that my supposed-to-be A4 page was, in Photoshop, larger than a A0 page :-/

It seems that simple-scan actually sets a 72dpi resolution, disregarding the resolution you actually used to scan your document. Here is the output of `identify -verbose` on a scanned document : http://pastebin.com/7PQ8kWyk

When using mogrify from ImageMagick (`mogrify -density 150x150 <filename>`), we can force resolution in PNG headers. `identify -verbose` then rightly reports a 150x150 resolution but Photoshop is still not able to import it at the correct size (A4).

You will find attached an example of scanned document (some random chip-card of mine, actually) saved as PNG (but before I forced the PNG headers to 150x150)

Am I missing something ? Or is it a bug ?
I might run some more tests if it helps.

PS : I'm using an Epson Stylus SX445W
PS2 : AFAIK, resolution is correctly set when saving as PDF file, but there is the same bug when saving as JPG image.
PS3 : I'm using simple-scan-3.6.0-ubuntu1_amd64 from an up-to-date Lubuntu 12.10

[Michael Nagel (nailor)]

please state if and how this is different from Bug #484616
if it is not, please merge.

[Michael Baudino (gornack)]

It 's definitely the same bug !
Sorry I could not find it while searching an existing bug before posting.