Dividing the pixel into blocks

I have an image say which i have uploaded now i want to resize that RGB image and divide pixels having same value into blocks

for example in the image uploaded of arabian sea ,it consists of water(blue) ,sand(brown) ,leaves,and more

so i want to divide water(blue) into block,sand(brown)into another block and so on please help

http://imgur.com/kGlgu,mT90e#0

Answer 1

[Ryan]

Do you have the image processing toolbox? This should get you started down the right path:

• Color-Based Segmentation Using the L*a*b* Color Space
• Color-Based Segmentation Using K-Means Clustering
• More on segmenting in a*-b* space
• Great for beginners: Image Segmentation Tutorial ("BlobsDemo")
• Color segmentation by Delta E color difference

Answer 2

[Image Analyst]

In addition to the nice links Ryan gave, you might look at the rgb2ind() function in MATLAB, which I believe does something like what's described in this link:

http://en.wikipedia.org/wiki/Color_quantization

Also take a peek at the quadtree() function. It doesn't classify but just finds "uniform" areas.