jpegcrop problem?

[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!

[xnview]

If you use jpegcrop, the X,Y, W, H must be a multiple of 8

[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?

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 ?

[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....