Picture Letter Recognition software

This program is able to recognize characters in a picture
1.2K Downloads
Updated 2 Apr 2012

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This is just the start of what I want to do with a letter recognition program. To run it, save the files in a folder and run the program. It will analyze the picture and compare it to a set of values taken from a letter database to output the letters.

If you want to test its accuracy, open up paint and write anything in Calibri with capital letters. Try sticking with a font above 20 in paint because when uploading it to matlab, small fonts wont be represented as well in the 3 by 3 rgb translation.

The way I set the program up will allow it to run with other fonts, you just have to update the file called letter profiles with other fonts.

How I did it:
When uploading a picture text to matlab, it will be presented as a 3 by 3 matrix with numbers ranging from 0 to 255. The first thing I did was manipulate these numbers to be either 0 or 255. This made analyzing the picture easier. Then I found the the upper and lower limits of each line and stored them as an array. With this data I found the left and right limits of each character. From here, I was able to filter out the letters into sub matrix's to be analyzed.
The way I analyzed these letters was by looking at each side of the letter (top bottom left right) and then seeing what shape they made. From here I ran the program to see the shape of the alphabet and I stored that as letter profiles.
This is were it got a little tricky because I had to use a spline command and a way of normalizing the data to adjust for different font sizes and different letter dimensions.

From here I compared the picture letters with the letter profiles and outputted which letter it was.

Cite As

nathanial hapeman (2026). Picture Letter Recognition software (https://www.mathworks.com/matlabcentral/fileexchange/35975-picture-letter-recognition-software), MATLAB Central File Exchange. Retrieved .

MATLAB Release Compatibility
Created with R2010a
Compatible with any release
Platform Compatibility
Windows macOS Linux
Version Published Release Notes
1.0.0.0