RFR: 8338153: java/awt/Checkbox/CheckboxCheckerScalingTest.java test failed on linux machine

[Tejesh R]

On Wed, 28 Aug 2024 09:35:13 GMT, Abhishek Kumar <abhiscxk at openjdk.org> wrote:

>> Test failed intermittently on particular host. Though analysis pointed out to a test frame at left top on that host, I've updated the test for further stabilizing it. Two things done here:
>> 1. Move the frame to center of the screen rather than left top.
>> 2. Added tolerance checks for color comparison - this is based on analysis reports where the image didn't had exact black color which is supposed to be. So like other test cases, providing some tolerance for comparison.
>
> test/jdk/java/awt/Checkbox/CheckboxCheckerScalingTest.java line 78:
> 
>> 76:                         for (int j = 0; j < imageAfterChecked.getWidth(); j++) {
>> 77:                             Color pixelColor = new Color(imageAfterChecked.getRGB(i, j));
>> 78:                             if (compareColor(pixelColor)) {
> 
> Current pixel comparison suggests that the test passes even if one pixel satisfies the condition. This may give some false positive result.
> Is it possible to test all pixel and then check the number of pixels passed against total number of pixels compared and if it is more than some percentage value ( may be ~85-90) then return true otherwise false.
> 
> This may lead to avoid the tolerance check if sufficient number of pixels are exactly black in color.

Checker mark will be less than 50% of the image. The image captured is around 8x8 pixels, in that we hardly can find 10% of black color (though with tolerance of 5-10 value). Since we are making decisions based on black color which is the actual checker color with tolerance, checking for one such match would be fine.

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PR Review Comment: https://git.openjdk.org/jdk/pull/20723#discussion_r1734357861