13298 Picture Compare Difference inaccuracy

[chrisjj]

At some soom values, the Difference display can be pixel-inaccurate with respect to the left and right displays e.g. 150%

http://img268.imageshack.us/img268/2580/4diffsbpngpicturecompar.png

100% and 200% is fine.

[Aaron]

Hello Chris,

Different Zoom levels can display files differently. By zooming to a specific level, the picture must compress specific pixels into a smaller space, and pick which pixel should represent the multiple pixels.

The comparison is still accurate. Changing the zoom level does not affect the comparison, only the preview of the file.

[Aaron]

If you do not think that is the issue and for us to investigate further, please attach or email us the pair of picture files so we can test with them in house. If you email us at [email protected] , please also include a link back to this forum post for our reference. Thanks.

[chrisjj]

> Different Zoom levels can display files differently.

The difference in display is not across different zoom levels. It is within the same zoom level. There is no excuse for different panes of the same zoom level showing inconsistent pixel rendering.

> please attach or email us the pair of picture files so we can test with them in house.

Did you have a problem reproducing this? It happens on every image I've tried.

[Aaron]

Most of my sample pictures are more complex, and it doesn't appear to be happening, but I don't have a simple waveform on a white background.

[chrisjj]

> I don't have a simple waveform on a white background.

See the screenshot in the original report. Copy and paste to BC. Viola.

[Aaron]

Hello Chris,

I can see something at 150%, but the screenshot is already captured at 150% zoom level. We'd need the original picture files as a good sample test case.

[chrisjj]

OK, since I no longer have that file, here's another case:

http://img30.imageshack.us/img30/5453/6orientdiffsbpngpicture.png

and its picture file (same both sides):



Good luck in getting this remedied.

[Aaron]

This is an issue with the 150% zoom level in our 3rd party image viewing library for the two outer panes. We'll keep an eye out for this issue in any updates to the library.

[chrisjj]

I hope you'll also pursue a fix. Thanks Aaron.