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### Author Topic: how to find a specific color in a image through matlab  (Read 7147 times)

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#### karmax

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##### how to find a specific color in a image through matlab
« on: June 04, 2009, 03:23:27 AM »
hi ... i have an image of red lines whose junction is blue as you can see in pic. actually i want to find out all the cordinates of blue point with respect to any point.image size always be 420 X 720.i attached one of the sample pic.please help me out.
thanks

#### fiflak666

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• My native language isn't english :P
##### Re: how to find a specific color in a image through matlab
« Reply #1 on: June 04, 2009, 01:20:15 PM »
what's the problem?
you just have to move from one corner (0,0) of the image to the other (dim_x,dim_y) and with every piksel check if its RGB values say that it's blue (assuming that it's 8-bit color depth it's gonna be something around RED 0, GREEN 0 BLUE 255)

if so, you've found blue point - remember its coordinates and go along with your checking

#### karmax

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##### Re: how to find a specific color in a image through matlab
« Reply #2 on: June 16, 2009, 01:33:03 AM »
i want to thin this image so line contains in single pixel instead of 2 pixel in left and right.i applied sobel on this image an i got underattached image.please help out.

#### awally88

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##### Re: how to find a specific color in a image through matlab
« Reply #3 on: June 16, 2009, 02:09:25 AM »
Quick question, you're not using jpeg for the actual analysis are you? Because otherwise everything will die because of the lossy compression algorithm that jpeg uses.

I don't know much about imaging algorithms but isn't sorbel mainly used for edge finding complicated pictures? I don't know how it will go thinning pixels from an image. Do you have some code you can attach so we can check it out?
« Last Edit: June 16, 2009, 02:10:38 AM by awally88 »

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