get selection coordinates

[romankr]

Hi.. I need some help to build the proper command line code.

I have an image that have black borders, i need to select those black borders and get the selection coordinated.

here is a print screen that have such a selection: http://img137.imageshack.us/img137/9103/pic1j.png

so i just need to do that kind of selection and get the coordinates.

Thanks.

[fmw42]

I don't think IM can find the coordinates of the boundary around the black and return them to you. But you can easily trim the black areas to smallest image area and/or change the black to transparent. You can even make a mask of the non-black vs black areas and use that mask to merge images.

Can you explain why you need the coordinates?

[romankr]

Hi, thanks for your reply..

I'll explain why do i need the coordinates, maybe there is a better way to do what i need.

I'm trying to build an image cropper that will crop where the red lines in that image:
http://img339.imageshack.us/img339/9673/pic2t.png

so i need to know the high and low point of the black background.
maybe you have an idea on other way i can do that?

Thanks

[fmw42]

-trim will crop out as much black as possible so that the non-black areas will bound the image.

convert image.png -trim result.png

see http://www.imagemagick.org/script/comma ... s.php#trim

[anthony]

Warning the PNG result will probably contain the trim offset information. Using +repage after -trim or -crop is recommended to remove that information unless you actually want to see what was trimmed.