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### Re: Can i Compare two images in perl ?

by BrowserUk (Pope)
 on May 30, 2011 at 17:28 UTC ( #907344=note: print w/replies, xml ) Need Help??

in reply to Can i Compare two images in perl ?

a way to compare two images by finding out the degree of difference b/w them

That is a really open ended question that will need a lot of clarification.

For example:

1. What degree of similarity would you ascribe to these two images? A, B

These two are from a 'spot the differences' competition and have 10 substantial differences. Elements have changed color; things have changed position.

How similar do you want to consider the two?

2. How about these two? A, B

This is more subtle. The two images are identical in their content, but the color of every pixel in the picture is slightly different. So if you do a simple numerical comparison, they would be rated as 100% different.

Do you want them assessed as 100% different?

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

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Re^2: Can i Compare two images in perl ?
by deep3101 (Acolyte) on May 30, 2011 at 18:25 UTC
actually kind of both to some extent... actually they are graphs generated from some source and have background of many greyish curves but an average curve derived from the constituents is formed in a prominent colour, so i need to find similarity/difference(threshold level would do) between them even if a single colour channel is considered i think my purpose will be solved.
they are graphs generated from some source and have background of many greyish curves but an average curve derived from the constituents is formed in a prominent colour,

If you posted (offsite) a couple of examples. Say, one pair that you want considered substantially similar, and another that want considered substantially different, then you would likely get much better suggestions for how to approach the problem.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

Can you not work with the data that was used to form the image rather than futsing about with image recognition techniques? Sounds like you are trying to apply a solution that is "easy" for humans therefore easy to express in a way people understand, but is very difficult to code. You may be much better describing the problem in a numeric domain which may be harder to think about, but will be much easier to code.

True laziness is hard work
The quote was amusing but the technique requires manually comparing many images generated from a software for a technique in bioinformatics, plus the software just gives the output as image files only so no easy way out i guess other than Hard Work..

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