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jpegcrop problem?

Posted: Wed Mar 04, 2009 6:50 pm
by SElsner
Hello,

I want to use jpegcrop option for cropping images, which are 2048x1556 to 2048x1280 (centered in original image). the command line option would be -jpegcrop 0 138 2048 1280, right? 138 is the crop from the top of the image, i suppose. but what i get is an image with 1290 pixel height. If i use 128 instead of 138 it works! What am I missing?

Trying other images I get 1282 or other values?! Whats wrong? Or is this a normal behaviour?

Thanks

Sebastian

PS.: Not to leave a wrong impression: nconvert is a great tool!

Re: jpegcrop problem?

Posted: Thu Mar 05, 2009 11:03 am
by xnview
If you use jpegcrop, the X,Y, W, H must be a multiple of 8

Re: jpegcrop problem?

Posted: Sat Mar 07, 2009 2:14 am
by DOS386
If i use 128 instead of 138 it works! What am I missing? Trying other images I get 1282 or other values?! Whats wrong? Or is this a normal behaviour?
xnview wrote:If you use jpegcrop, the X,Y, W, H must be a multiple of 8
Lossless JPG cropping works on complete blocks the JPG consists of that are 8 x 8 pixels in size and aligned top left, ... nevertheless, don't I need even worse a multiple of 16 if the JPG is subsampled ? :?

Posted: Mon Mar 09, 2009 9:16 am
by SElsner
Problem is, if I 136 from the top (as y) and 1280, which are both dividable by 8 i get a cropped picture with the height of 1288....