Welcome Guest! You need to login or register to make posts.

Notification

Icon
Error

Options
Go to last post Go to first unread
kpgraci  
#1 Posted : Wednesday, April 5, 2023 9:39:38 AM(UTC)
kpgraci

Rank: Newbie

Groups: Member
Joined: 4/5/2023(UTC)
Posts: 1

Thanks: 1 times
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.

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

Rank: Advanced Member

Groups: Member, Administration, Moderator
Joined: 9/19/2006(UTC)
Posts: 505

Was thanked: 41 time(s) in 41 post(s)
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)
Users browsing this topic
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.