0.98.4: PCX files not displayed correctly (artifacts)

[GeckoN]

XnView: MP 0.98.4 - 32 bit
OS: Windows 10 64bit

Loading a PCX file generated by SpeedSys (PC benchmark for DOS) results in a corrupted image being displayed in the viewer.

Effect: Corrupted display in the viewer. The browser window gives somewhat better results but the aspect ratio appears to be wrong no matter what sizing option is selected.

To reproduce:
1. Extract the attached ZIP file (SSTIMG01.zip)
2. Open the contained PCX file (SSTIMG01.PCX) in the viewer
Actual behaviour (bug): Corrupted display in the viewer (artifacts, stretched picture, see xnviw.png)

Expected behaviour: The loaded image being displayed correctly (see irfanview.png)

Note: It's possible that the PCX files generated by the SpeedSys application are somewhat non-standard, but other viewers seem to be able to open them just fine (i.e IrfanView 4.56).

[xnview]

Strange, i can't reproduce, lastest version?

[GeckoN]

Yep, 0.98.4. But I had the same problem with version 0.98.2. Updating to the latest build didn't fix the problem.

I could try a clean install or a different machine. Or can you tell me which binary is responsible for loading PCX files?

[xnview]

I could try a clean install or a different machine.

yes please

[GeckoN]

Ok, I've backed up the original installation folder (as that's where my settings are stored) and then did a clean install. That made the problem go away initially, but it didn't really fix it.

I've copied my old xnview.ini file to the clean installation and the problem was back. By diffing the default clean config with my custom one I was able to narrow it down to the line that triggers the problem:

Code: Select all

zoomQuality=3

Setting zoomQuality to 2 or 3 is what causes the problem it seems (this corresponds to the "Zoom-in" and "Zoom-out & Zoom-in" "High zoom quality" settings). Also, the viewer window must be somewhat smaller than the actual picture for this to happen.

There's also one other issue related to the provided PCX file. The viewer displays it with an aspect ratio of 1:1 (stretched vertically), yet the software clearly knows its actual resolution (and aspect ratio) because the status bar area says "640x480x4 (1.33)". I have the "Pixel ratio" option set to "Square" - which should be the default option and should maintain the original aspect ratio (4:3 or 1.33) if I'm not mistaken. I can create a separate ticket for this problem if you want.

[xnview]

Ok, I've backed up the original installation folder (as that's where my settings are stored) and then did a clean install. That made the problem go away initially, but it didn't really fix it.

I've copied my old xnview.ini file to the clean installation and the problem was back. By diffing the default clean config with my custom one I was able to narrow it down to the line that triggers the problem:

Code: Select all

zoomQuality=3

Yes i can reproduce when zoom is 99%, there is a problem when depth <=8

There's also one other issue related to the provided PCX file. The viewer displays it with an aspect ratio of 1:1 (stretched vertically), yet the software clearly knows its actual resolution (and aspect ratio) because the status bar area says "640x480x4 (1.33)". I have the "Pixel ratio" option set to "Square" - which should be the default option and should maintain the original aspect ratio (4:3 or 1.33) if I'm not mistaken. I can create a separate ticket for this problem if you want.

yes please

[GeckoN]

There's also one other issue related to the provided PCX file. <snip>

yes please

Posted HERE.

And thank you for your fast response. Looks like XnView is not only a great piece of software, but it also has great support!