count letters in image file

i would like to count the number of letters present in an image which contains a bunch of lines of text. i know that somehow, i have to look at each individual pixel and see when the pixel value changes from 0 to 1 (black to white) and then increment a count.

but because different letters look so different from one another, i am really not sure of the algorithm to use here.

any suggestions?

Answer 1

[Image Analyst]

Simple blob analysis is difficult because some letters are composed of multiple blobs, like i and j. So you need to recognize the letters. Try this: http://www.mathworks.com/help/vision/ref/ocr.html#bt548t1-2_1

[Scott]

the only thing is that i am trying to do this manually, rather than using a tool like OCR

[Image Analyst]

OK. Good luck. Writing your own OCR can be challenging, but good luck with it.