VNG vs Bilinear deBayer - is there a problem

[astropixel]

Hi. Here is the same flat converted to grayscale, debayered and background extracted.

On the left VNG. On the right Bilinear.

I see the definition with VNG vs Bilinear, however, their is a preponderance of black dots on the VNG image. How should I interpret the difference - is this indicative of a problem with VNG debayering, though it is more accurate.

Not sure what I am looking at here.

Many thnks,

ap

[zvrastil]

Hi,

I'll take a look at it this evening. Any chance to get your bayered image? Some 200x200 crop would be enough (starting on left-top corner to keep bayer pattern origin).

cheers, Zbynek

[zvrastil]

Please take a look here http://pixinsight.com/forum/index.php?topic=3560.msg24479#msg24479. If it does not explain it, just let me know.

(Edit) - actually, Bilinear debayering is probably better choice for debayering flat frame. VNG is about keeping gradients, but there should be no steep gradients on flat frame. But it's quite exceptional case. For most real images, VNG should give better overall results.