I'm currently working on a personal project for decoding a text or any object in an image.
I'm using GD library for processing image. I have access to every pixel of image and its rgb color.
My question is not about coding,I'm just looking for an algorithm to decode image,or any advise for how to do that and I don't want to use any API, I want to do it by myself. I know that php has a face detection library, but it only recognizes faces in image, and I don't know how it does that .
for start, I assume that the object is white and the background is black (or any separate colors) .
summary : How can I define an object or a word for a php program and train it to recognize it from a picture?
You have some api which decode simple captcha like this.
Check this link : Captcha Decoded
And try with this api : http://www.opendecoder.com/api, there are many API if you search on google
The process you are trying to implement is called “optical character recognition” and there is some free software available and doing this. With this expressions, you may find more information.
You did not specify the kind of software component you are looking far, so it is hard to be more specific.
This is usually an error-prone process, but you might get better results if you can make regularity assumptions on your input, especially if you already know which character types are used in your input.
Useful starting points could be
http://jwilk.net/software/ocrodjvu http://unpaper.berlios.de/
If converting to DJVU and using python on a UNIX system is an option for you, you might consider a the first link as a solution. Otherwise you may use the various tools supported by ocrodjvu to start your research. The second is more about pre-processing you might want to do before OCR but still might be useful if you want to implement your own procedure.