Simple image analysis

I am looking for a method, software or library for simple image analysis.

The input image will be a white-colored background, and some random small black dots on it.

I need to generate a .txt file that represents these dots' coordinates. That is, if there are three dots in the image t开发者_JS百科he output will be a text file that includes somehow a representation of three coordinates, (x1,y1), (x2,y2), and (x3,y3).

I have searched the web for hours and didn't find something appropriate, all I found was complex programs for image processing.

I've been told that it's easy to write code for this mission in MATLAB, but I'm unfamiliar with MATLAB.

Can this be done easily with C++, Java or C#?

Any good libraries?

It is quite simple in any language. Depending on the form of your input, you probably need to go over all of it (assuming it is a simple matrix - simply have two nested loops, one for the x coordinate and one for the y coordinate), whenever you encounter a black dot - simply output the current indexes which would be the x and y coordinates for the dot.

As to libraries, anything other than something to decode your input to the form of such a matrix (e.g. a JPEG decoder) would be overkill.

I don't think you would need image processing libraries for this kind of problem (somebody correct me if I am wrong) since these libraries may focus on image manipulation and not recognition. What you will need is a knowledge of the image format that you are supporting (how are they stored, how are they interpreted, etc) and basic C file system functions.

For example, if you are expecting a JPG file format you will simply calculate the padding for each scanline and reach each scan line one by one, and each pixel in the line one by one. You'd have to use two counters, one for the row and one for the column. If the pixel is simply not white, then you have your coordinate

This is something which should be very easy for you to do without any external software; something like

for(y in [0..height]) {
   for(x in [0..width]) {
       if(pixels[y][x].color == BLACK)
           print("(%d, %d)", x, y);
   }
}

would work.

The bitmap file format is quite easy to read.

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

You could just stream the bytes into an array using this info. I've written a few BMP readers; it is a trivial matter.

Also, although I cannot vouch for its ease of use as I've never used it before, I've heard that EasyBMP works fine too.

CImg library shold help you. From CImg FAQ:

1.1. What is the CImg Library ?

The CImg Library is an open-source C++ toolkit for image processing.

It mainly consists in a (big) single header file CImg.h providing a set of C++ classes and functions that can be used in your own sources, to load/save, manage/process and display generic images. It's actually a very simple and pleasant toolkit for coding image processing stuffs in C++ : Just include the header file CImg.h, and you are ready to handle images in your C++ programs.