Effective resolution is 75 DPI despite selecting 600 or 1200.
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#264 Effective resolution is 75 DPI despite selecting 600 or 1200.
When I select a resolution of 600 or 1200 DPI to scan on my flatbed, the actual resolution is only 75 DPI. If I select any resolution of 300 DPI or lower, it works fine.
With Xsane, I can scan to 600 or 1200 DPI without any problem. It is as if gscan2pdf sends a command to the scanner to scan at 75 DPI when 600 or 1200 DPI is selected.
The device is the HP Officejet Pro 6978 All in one (recent model, recent purchase).
gscan2pdf 1.8.3.
hplip 3.17.6 installed (latest as of 2017-07-12).
Linux Ubuntu 16.04 LTS Xenial Xerus (all software up to date as of 2017-07-12).
Please start gscan2pdf from the command line with the --log=log option, reproduce the problem, quit, and attach the log file.
Attached, two files. One with 300 DPI selected which worked fine, the other with 600 DPI selected, but clearly the resolution scanned is much lower than that of the 300 DPI.
I think the problem is that US Letter has been rounded up to 216mm wide, but that your scanner backend only supports 215.9mm. Most scanners simply round down, but your scanner is producing an error when gscan2pdf selects 216mm, and I think that the resolution problems start there.
Please test this theory by editing your US Letter definition in gscan2pdf down to 215mm wide.
In the mean time, I'll add some code to gscan2pdf to round down (or up) where necessary.
I selected 'manual' and entered 215 x 279 and even tried 200 x 200, yet it always scan in 75 DPI when 600 DPI or 1200 DPI is selected. I redefined "US Letter" to 215 x 279 and got the same thing (no surprise here).
BTW, I found another bug. I could not edit the "US Letter" definition because when pressing apply, the "US Legal" definition was to high for the scanner. I suspect that the code aborts any update if an error exist. It should save those entries that are valid though. I had to delete "US Legal" to be able to fix "US Letter".
I can't reproduce your paper size editing bug.
Would you mind going through the steps to follow to reproduce the problem?
OK. Thanks for the feedback. Would you mind giving me another log file, this time with the smaller page size?
Last edit: Jeffrey Ratcliffe 2017-07-25
As requested, the log file when scanning 600 DPI with a 200 x 200 sheet.
What I don't understand is that according to the log, the flatbed is active from the start. i.e. it seems to start with source=flatbed and resolution=75/100/200/300, and then you select source=flatbed (somehow) and suddenly get resolution=75/100/200/300/600/1200.
Would you mind removing or renaming ~/.config/gscan2pdfrc starting gscan2pdf, and posting a screenshot of the scan dialog? Which source is default, and which resolutions?
Last edit: Jeffrey Ratcliffe 2017-07-26
Yep, there is definitely a problem here. At first, only resolutions 75/100/200/300 are available. Then I change the source for something else, like ADF, then switch back to Flatbed and voilà, resolutions 75/100/200/300/600/1200 are now available, but 600/1200 are not working.
Thanks. Please repeat the above, but without touching the paper or geometry options, just change the resolution to 600 and try to scan, quit and post the log file. In your most recent log file, you didn't scan.
Also, please try the libimage-sane-perl frontend (in edit preferences), which has better error handling.
For completeness sake what do
and
return?
Forget all of that. I've found the bug. I'll fix it for the next release, which I hope will be in the next few days.
I'll mark the bug as closed, as I have fixed the main problem. It should not stop you from replying about the paper size editing problem. If it does, please do not hesitate to open a new bug report.