Error in Pixel Values with Alpha

[John Stewien]

When I draw Pixels with Alpha they don't retain their proper value. To Reproduce in Paint.NET 3.36:

New Document

Select All and Clear

Select the Rectangle Tool

Select Draw Filled Shape

With the Colors Window select ARGB 65,255,255,255

Draw a Rectangle

With the Color Picker Tool sample the rectangle just drawn

You will get an ARGB of 65,254,254,254 so all the RGB values are 254 instead of 255

[silverhammer]

Weird, I just confirmed this. It seems to happen with many RGB values not just 255, though certain values do not change when you use the eyedropper. I can only assume that PdN stores colors in a different format than ARGB so some rounding occurs when you actually draw on the image. So I don't think that the eyedropper is picking up the "wrong" color, rather the color you're actually drawing is slightly different from the one you selected. So this bug shouldn't actually affect your drawings in any way as the visual difference between 254 and 255, for example, is essentially nothing.

[John Stewien]

So this bug shouldn't actually affect your drawings in any way as the visual difference between 254 and 255, for example, is essentially nothing.

Visually it might not be much different but it depends what you are using your images for. Paint.NET is a nice proggy for editing data that has been converted to image form. Unfortunately this issue is causing me grief.

[Rick Brewster]

It's a GDI+ issue. This bug has been reported before, and is a Won't-Fix until/if we change rasterizers (which we'd like to do eventually).