About the "Compare" function

[kct01]

Hi everyone!!!
I am doing a project about image comparison and I found that ImageMagick is very useful.
And I found that imagemagick got a "compare" function which can compare 2 images' differences.
However, I dun know how to implement it with java.
Can jmagick use the "compare" function?
Thank you!!

[anthony]

All languages, except possibly java can run other programs, so you could have it run the "compare" command itself.

NOTE however that if you plan to compare a lot of images then you face a 'N-squared' problem. that is to compare N images with every other image you need N*(N-1) or on the order of N^2 compares. That is a LOT of compares for even a small number of images!

Because of this you are better off generating small 'thumbnails' or some type of 'fingerprint' image to compare for speed. This will identify images that are 'close' enough that a full image comparison is warranted, without the full cost of always using full image compares.

See IM example pages on my notes on image comparing
http://www.imagemagick.org/Usage/compare/

I am sorry in that the notes are fairly rough, but their is a lot of ideas and techniques present in the page that could be used.

[kct01]

Thank you for answering.
I read the page that u mentioned before.
But still I dun know how to use that compare function with java.
Im a newbie in java programming. Would u mind tell me the details?
Thank you very much!!

[anthony]

Sorry don't know much about java or its API.

Perhaps one of the more specialized forum groups can help.

[kct01]

So, normally, the whole function of Imagemagick should be able to be used with different languages??
Do you know what I mean??

[anthony]

Yes all the image processing functions should be available in all API's of the library. However that is not always the case. Especially when new functions are involved.

[kct01]

I wonder if jmagick really use the "compare" or "difference" function of ImageMagick coz I can't find any related function here: http://downloads.jmagick.org/jmagick-doc/
Can somebody help!?!?!?!?