Re: Find similar images using python
On Fri, 31 Mar 2006 15:10:11 -0800, rumours say that Scott David Daniels [EMAIL PROTECTED] might have written: Christos Georgiou wrote: I did make a module based on imgseek, and together with PIL, I manage my archive of email attachments (it's incredible how many different versions of the same picture people send you: gif, jpg in different sizes etc) and it works fairly well. E-mail me if you want the module, I don't think I have it currently online anywhere. This sounds like a great recipe for the cookbook: http://aspn.activestate.com/ASPN/Cookbook/Python Actually, it should go to the CheeseShop, since it is a python module that is a bridge between PIL and the C module (I don't believe multi-file modules are appropriate for the cookbook, but ICBW); however, my web space is out of reach for some months now (in a web server at a previous company I worked for), and I'm in the process of fixing that :) -- TZOTZIOY, I speak England very best. Dear Paul, please stop spamming us. The Corinthians -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
Thomas W wrote: How can I use python to find images that looks quite similar? Thought I'd scale the images down to 32x32 and convert it to use a standard palette of 256 colors then compare the result pixel for pixel etc, but it seems as if this would take a very long time to do when processing lots of images. Any hint/clue on this subject would be appreciated. This really depends on what is meant by quite similar. If you mean to the human eye, the two pictures are identical, as in the case of a tool to get rid of trivially-different duplications, then you can use the technique you propose. I don't imagine that you can save any time over that process. You'd use something like PIL to do the comparisons, of course -- I suspect you want to do something like: 1) resize both 2) quantize the colors 3) subtract the two images 4) resize to 1x1 5) threshhold the result (i.e. we've used PIL to sum the differences) strictly speaking, it might be more mathematically ideal to take the sum of the difference of the squares of the pixels (i.e. compute chi-square). This of course, avoids the painfully slow process of comparing pixel-by-pixel in a Python loop, which would, of course be painfully slow. This is conceptually equivalent to using an epsilon to test equality of floating point numbers. The more general case of matching images with similar content (but which would be recognizeably different to the human eye), is a much more challenging cutting-edge AI problem, as has already been mentioned -- but I was going to mention imgSeek myself (I see someone's already given you the link). -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
On 29 Mar 2006 05:06:10 -0800, rumours say that Thomas W [EMAIL PROTECTED] might have written: How can I use python to find images that looks quite similar? Thought I'd scale the images down to 32x32 and convert it to use a standard palette of 256 colors then compare the result pixel for pixel etc, but it seems as if this would take a very long time to do when processing lots of images. I see someone suggested imgseek. This uses a Haar transform to compare images (check on it). I did make a module based on imgseek, and together with PIL, I manage my archive of email attachments (it's incredible how many different versions of the same picture people send you: gif, jpg in different sizes etc) and it works fairly well. E-mail me if you want the module, I don't think I have it currently online anywhere. -- TZOTZIOY, I speak England very best. Dear Paul, please stop spamming us. The Corinthians -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
Christos Georgiou wrote: I did make a module based on imgseek, and together with PIL, I manage my archive of email attachments (it's incredible how many different versions of the same picture people send you: gif, jpg in different sizes etc) and it works fairly well. E-mail me if you want the module, I don't think I have it currently online anywhere. This sounds like a great recipe for the cookbook: http://aspn.activestate.com/ASPN/Cookbook/Python -- -Scott David Daniels [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
Finding similar images is not at all a trivial task. Entire PhD dissertations have been committed to it. The solutions are still very unreliable as of yet. If you want to find more, you can read the research out of the ongoing Image CLEF track. I worked with them briefly a couple of years ago in context of medical images. http://ir.shef.ac.uk/imageclef/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
Richie Hindle [EMAIL PROTECTED] writes: [Thomas] How can I use python to find images that looks quite similar? Have you looked at http://www.imgseek.net/ ? It's an Open Source Python photo collection manager that does exactly what you're asking for. Maybe... I don't recall if it had a duplicate search feature. What I remember is the GUI in which you scribbled a picture, and asked it to pull up images that looked like that. Amusing, though didn't seem to work terribly well. No bad reflection on the author: it's a hard problem of course. John -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
John J. Lee schreef: Richie Hindle [EMAIL PROTECTED] writes: [Thomas] How can I use python to find images that looks quite similar? Have you looked at http://www.imgseek.net/ ? It's an Open Source Python photo collection manager that does exactly what you're asking for. Maybe... I don't recall if it had a duplicate search feature. What I remember is the GUI in which you scribbled a picture, and asked it to pull up images that looked like that. Amusing, though didn't seem to work terribly well. No bad reflection on the author: it's a hard problem of course. It does have a duplicate search feature (see screenshot http://www.imgseek.net/sshot/e1c93fe060c6622a6aee90a22921c49a.png for example), though I don't know how well it works. -- If I have been able to see further, it was only because I stood on the shoulders of giants. -- Isaac Newton Roel Schroeven -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
Use PIL..of course.. Sudharshan S -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
Thomas W wrote: How can I use python to find images that looks quite similar? Thought I'd scale the images down to 32x32 and convert it to use a standard palette of 256 colors then compare the result pixel for pixel etc, but it seems as if this would take a very long time to do when processing lots of images. Any hint/clue on this subject would be appreciated. This question is immensely non-trivial unless you can form a precise definition of images that look quite similar. It is one of those deceptive problems that seem straightforward, but become less and less well-defined the more you study it. If you can solve this you can get a PhD, get rich, get famous, or a combination of all three. The US Supreme Court gave up on identifying pornography, because the best definition anyone ever came up with was I know it when I see it, a judgment quite reasonable in a legal system based on trusted authorities, but not a good one in a society ruled by laws and not men. --Scott David Daniels [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
Thomas W wrote: How can I use python to find images that looks quite similar? Thought I'd scale the images down to 32x32 and convert it to use a standard palette of 256 colors then compare the result pixel for pixel etc, but it seems as if this would take a very long time to do when processing lots of images. Any hint/clue on this subject would be appreciated. You are aware that this is one of the most sophisticated research areas in CS in general? Your approach is by no means appropriate for even the slightest of differences in the image - after all, your only reducing resolution. That doesn't e.g account for different lighting conditions - you wouldn't be able to connect a still photograph of a house taken by a mounted camera at dusk and at dawn. And so on. So as long as you don't have a _very_ homogene image source, this is a way more complicated task - if not undoable. Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
I dont get it..cant the matching take place efficiently with PIL, only that you need to have a condition i.e if the mismatch exceeds a certain threshold, they are not similar, http://gumuz.looze.net/wordpress/index.php/archives/2005/06/06/python-webcam-fun-motion-detection/ Check the above link, only diiference is that instead of files as in ur case, the code here compares two pixels of consecutive frames for changes.. Sudharshan S -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
[EMAIL PROTECTED] wrote: I dont get it..cant the matching take place efficiently with PIL, only that you need to have a condition i.e if the mismatch exceeds a certain threshold, they are not similar, http://gumuz.looze.net/wordpress/index.php/archives/2005/06/06/python-webcam-fun-motion-detection/ Check the above link, only diiference is that instead of files as in ur case, the code here compares two pixels of consecutive frames for changes.. No, the difference is fundamental: two consecutive frames of a still-mounted camera are - except noise and changing lightning conditions - the same. detecting a difference in case of motion is easy. But similarity between two images is a totally different beast. I would say that an image of my grandma with me on her knee and another one with my brother are very similar. But your approach would certainly fail to say so... diez -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
[Thomas] How can I use python to find images that looks quite similar? Have you looked at http://www.imgseek.net/ ? It's an Open Source Python photo collection manager that does exactly what you're asking for. -- Richie Hindle [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
I did this once for a motion dection algorithm. I used luminescence calculations to determine this. I basically broke the image into a grid of nine (3x3) areas and calculated the luminescene for each section and if it changed signficantly enough then there has been motions. The more sections, the more precise the detection will be. This was written in Visual Basic 4 and was able to do about 10 frames per seconds so you can get decent performance. I got the luminescence calculation from a classic math/computer science equation book. I should know the title but I'm blanking on it. Andy -- http://mail.python.org/mailman/listinfo/python-list
Re: Find similar images using python
How can I use python to find images that looks quite similar? Thought I'd scale the images down to 32x32 and convert it to use a standard palette of 256 colors then compare the result pixel for pixel etc, but it seems as if this would take a very long time to do when processing lots of images. Any hint/clue on this subject would be appreciated. A company I used to work for has been doing research in this area (finding differences between images) for years, and the results are still hardy generalizable, so don't expect to get perfect results after a weekend ;-) I'm not sure what you mean by similar: I assume for the moment that you want to detect if you really have the same photo, but scanned with a different resolution, or with a different scanner or with a digital camera that's slightly out of focus. This is still hard enough! There are many approaches to this problem, downsampling the image might work (use supersampling!), but it doesn't cover rotations, or different borders or blur..., so you'll have to put some additional efforts into the comparison algorithm. Also, converting the images to a paletted format is almost definitly the wrong way - convert them to greyscale, or work on 24 bit (RGB or HSV). Another approach that you might try is comparing the image histograms: they aren't affected by geometric transformations, and should still contain some information about the original image. Even if they aren't sufficient, they might help you to narrow down your search, so you have more processing time for advanced algorithms. If you have performance problems, NumPy and Psyco might both be worth a look. -- http://mail.python.org/mailman/listinfo/python-list
