divide image into horizantal blocks

i want to divide image horizantaly lines to hide text, and select postion depended on mse to hide subtext; i mean if i had a text of 12 char 12/4=3>>no of blocks and image of [4*4] i want to hide each 4 char in block so ,blocksize/4=16 (3 blocks of size 16)

now i want to find positions to hide each 4 char in each block (mse=cover-stego/text) but these postions should not doublicat .. help me please

Answer 1

[Image Analyst]

I don't understand the English or what you want to do - perhaps if you can get a native English speaker to look it over and re-word it. All I got out of it is that you want to hide text in an image, and I've uploaded code for that into my File Exchange: http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862&sort=downloads_desc

[mary m]

thank you sir ,yes i want to hide text in image , but i want to divide RGB image into lines horizontally . i do it but it will be gray and that i dont want .

[Image Analyst]

Again, I don't understand. The RGB image already has lines, and it has columns too.

I don't know what you did to turn it gray. Of course if you just extract one color channel, that channel will be monochrome (gray scale).

[lotus whit]

Could you please tell me how I can do vertical sliding window as shown in attached image with specific width and length? I applied the mat2cell() method but I don't know how I can modify to get the result.

[Image Analyst]

To get a small sub-image, tall and skinny or whatever, simply index:

subImage = grayImage(row1:row2, col1:col2);

You need to figure out what row1, row2, col1, & col2 need to be for each sub-image.