PNG export resolution problem

Bug #1096378 reported by Michael Baudino
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Simple Scan
Incomplete
Undecided
Unassigned

Bug Description

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

Revision history for this message
Michael Baudino (gornack) wrote :
description: updated
Revision history for this message
Michael Nagel (nailor) wrote :

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

Michael Nagel (nailor)
Changed in simple-scan:
status: New → Incomplete
Revision history for this message
Michael Baudino (gornack) wrote :

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

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