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#1 Posted : Wednesday, April 5, 2023 9:39:38 AM(UTC)

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Hey all,

I have jpeg images (art files) that are slightly larger or slightly smaller than the desired size (within 5%) and in those cases I need to crop (when the image is too large) or stretch (when the image is too small, this case is more rare).

I am doing this now with good results using native vb.net image/bitmap classes, and the jpeg encoder

However, no matter how I set the quality setting there is some color fading that occurs. It is not a lot, but there is noticeable difference. The actual quality is not bad but I need to be 100% faithful to the original image.

Can a vb.net solution offered by Graphics Mill take a jpeg and crop it without changing the color quality, depth, DPI, or anything else that would allow someone to see a difference in the images with a side by side comparison, specifically in color qualify depth, brightness, and whatever other attributes colors can have?

My goal is a 100% identical quality image that has some data cropped from the sides. There is also the less common case of slightly enlarging a jpeg image, with the same 100% color matching capability.

Eugene Kosmin  
#2 Posted : Wednesday, April 5, 2023 6:40:24 PM(UTC)
Eugene Kosmin

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Hi Ken,

I don’t think it’s possible to get 100% matching because of the lossy nature of the JPEG format. Every time you re-save a JPEG you get quality reduction.

What you can do to make the difference perceptually invisible:
  • Make sure you don’t lose the color profile during re-save. Especially if you work with CMYK or non sRGB profiles. It may be a cause of faded colors.
  • Use high quality writing.
Best regards,
Eugene Kosmin
The Aurigma Development Team
thanks 1 user thanked Eugene Kosmin for this useful post.
kpgraci on 4/11/2023(UTC)
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