Connected component labeling for 24-bit bitmap Image

Connected component labeling is an application where we search the pixel of same pixel value and if found then labeled them with same value .Thus the whole image is processed and the pixels having same value shows the same label.This is also known as blob extraction,region labeling .Connected component labeling  is used in computer vision to detect connected region in binary digital image or color image.There is two method used for connected component labeling 4-way connectivity and 8-way connectivity .In 4-way connectivity the top,bottom ,right and left neighbors are checked while in 8-way connectivity all 8-neighbors are checked and the lowest label is given to the same neighbor .Thus the whole image is traversed and we get a labelled image.
                                          

  Here is the output of a labeled pixels of an image.We can see here the pixels with same color have same      

label.