[Regression] Region total NumPixels is not consistent in the Ubuntu for the wide field matched images

[acdo2002]

Describe the bug This is the regression bug (only happened started from the commit de4da528). In the Ubuntu 22.04 system (not happened in the MacOS 11 and MacOS 13), if you open the two matched images, and set the region close to the edge, the total NumPixels are different. If the region is slight offset from the edge, the difference disappears, only happened in the region close to the edge.

To Reproduce Steps to reproduce the behavior:

1. Open two same images: casa_wideField.fits and casa_wideField.image (download link)
2. Spatially matched two images
3. Set a rectangle region (region # 1): Image coordinate, x centre is 300 px; y centre is 200 px; x size is 400 px; y size is 400 px
4. Click the "Statistics Widget" on the top and select Region # 1, and click the Image (switch casa_wideField.fits and casa_wideField.image ) and check the NumPixels

Expected behavior NumPixels should be the same between two matched (the same, only format is different) images The related ICD-RxJS is in the branch mylin/#Add-part2 (not merged yet), src/test/MATCH_STATS_WIDE_BORDERLINE.test.ts (link)

Platform info (please complete the following information):

• OS [e.g. macOS Monterey]: Ubuntu 22.04
• Browser [e.g. chrome, safari, electron app]: chrome
• Browser version [e.g. 22]: 124.0.6367.119
• Backend branch [e.g. dev, v3b2 release]: dev
• Frontend branch [e.g. dev, v3b2 release]: dev

Additional context Add any other context about the problem here.

[acdo2002]

Additional context Here is the screenshot to show how to reproduce this behavior. You can see if open the same image and spatially matched, set a specific region x centre in 300px; y centre in 200px; x size is 400px; y size is 400px The total NumPixels is different, one is 160801 another is 160401. abs(160801 - 160401)/160801(macOS provide this value)*100 = 0.25% uncertainty However is you shift 1px in y centre like to following screenshot Then the total NumPixels becomes the same.

Updated:

1. The total NumPixels inconsistent only happened in the rectangle region. Other RegionTypes (ellipse and polygon) does not have this problem.
2. This behavior is also happened for the small region, e.g. Image coordinate, x centre is 3 px; y centre is 1 px; x size is 4 px; y size is 2 px The total NumPixels inconsistent is still there, one is 15px another is 11px (macOS are always show 15px) abs(15-11)/15*100 = 26% uncertainty

Kuo-Song mentions it is the expected sampling problem for the wide field images. I leave the behavior I found here.