Bitmap file modification

[HSE]

Hi all!

Somebody know how to change one color for another inside a 24 bits Bitmap.

I have a little problem to understand pixel array 

Test is after an AW27 code.

Thanks in advance, HSE

[NoCforMe]

Sure. The things you need to know about how bitmaps are formatted are these:

• All lines of bitmap data must align to a 32-bit boundary, so there might be padding (zeros) on each line
• 24-bit bitmap data is just that: each pixel is 3 bytes, plus whatever padding is needed to bring the line to a 32-bit boundary. The pixel data is packed (no padding between pixels).

A 24-bit bitmap will have no palette, so you don't need to mess what that.

In your case, since your bitmap is 10x10, each line is 30 bytes of data, so there are 2 bytes of padding on each line. As they say, I leave it as "an exercise for the reader" to determine programmatically how much padding, if any, there is.

To change a color in a bitmap, locate the bitmap array, cruise through it line-by-line, looking at each pixel (3 bytes) and replacing them as you wish. Be sure to take the padding into account. Probably the easiest way is to calculate the "stride", which is the actual distance from the beginning of one line to the beginning of the next line.

Is this enough to get you started? I've been playing with bitmaps quite a bit recently, so may be able to help you further.

[HSE]

Thanks, NoC!

All lines of bitmap data must align to a 32-bit boundary, so there might be padding (zeros) on each line

That was the strange thing