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 Divide Blend Method
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Christoph

Germany
4 Posts

Posted - Jun 15 2023 :  03:04:27  Show Profile  Reply
Hello All,
Hello ImageEn Team,

I have a poorly lit picture that I need to evaluate. Unfortunately, I cannot change the lighting. To improve the image, I tried the Divide Blend Method in Photoshop. It gives an acceptable result. The original image is offset against a reference image (background).

f(a,b) = (b ÷ a) * 255)
or with a weighting of the reference image
f(a,b) = (b * 0.5 ÷ a) * 255

Is there an implementation like this formulas in ImageEn?

I tryed this but I only get Black results.

RefImg.RenderToTIEBitmapEx(ImageEnView1.IEBitmap, 0, 0, RefImg.Width,
RefImg.Height, 0, 0, RefImg.Width, RefImg.Height, true, 255, rfNone,
ielDiv, 1);

Do you have any Ideas?

Thank you and best regards
Christoph

Christoph

xequte

38684 Posts

Posted - Jun 15 2023 :  06:40:35  Show Profile  Reply
Hi Christoph

What is the content of your RefImg?

Have you tried any of the other brightness rendering options:

http://www.imageen.com/help/TIEBitmap.Contrast.html
http://www.imageen.com/help/TIEBitmap.BlackValue.html
http://www.imageen.com/help/TIEBitmap.WhiteValue.html


Nigel
Xequte Software
www.imageen.com
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Christoph

Germany
4 Posts

Posted - Jun 16 2023 :  02:01:38  Show Profile  Reply
Hi Nigel,

the reference image (RefImg) contains only the illuminated background, a white painted surface. If the lighting were optimal, the reference image would have to be white. But it is brighter in the middle than at the edge. (bad lamp and vignetting)
I place the object to be analyzed on this background and create the second image (ImageEnView1). The lighting remains as in the reference image. The object is of course not properly illuminated.
I would now like to use the Divide Blend Method to compensate for the differences in brightness. This works in Photoshop according to the given formulas.
Of course, I can also calculate the images pixel by pixel using the formula. But I thought that this function maybe already implemented in ImageEn.

Thank you and best regards

Christoph
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xequte

38684 Posts

Posted - Jun 16 2023 :  03:59:28  Show Profile  Reply
Hi Christoph

It sounds like our algorithm is different from what you are looking for. You should test your own algorithm, and if it works well we can include it as a blend option in ImageEn.

Nigel
Xequte Software
www.imageen.com
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Christoph

Germany
4 Posts

Posted - Jun 16 2023 :  06:21:16  Show Profile  Reply
Hello Nigel,

Ok, I will do an own implementation and send it to you if it works.

Best regards

Christoph
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