GLUT Creating a binary / RAW image file - image

Question

I have question about creating a binary / raw image file.
I've made an image in photoshop and now I want to load that in a C program.
I followed this tutorial http://www.nullterminator.net/gltexture.html but I don't know how to convert my own image to a .RAW file.
Can anyone help me out with this question?

Answer 1

Download ImageMagick, it is a command-line utility that can convert images into all kind of ways. And it supports many platforms.
So you could save your file in Photoshop to for example a PNG file, then run the following command to convert it to raw grayscale 8 bit:
convert MyImage.png -depth 8 gray:MyRawImage.raw

Answer 2

Try Save As and selecting RAW from the format drop-down. Humorously, it is listed under "P" for Photoshop RAW.
I don't know if it is the right kind of RAW which GLUT requires...

Answer 3

This worked for me, with that tutorial code:
Open your image in GIMP
Go to Layer/Transparency/Remove Alpha Channel. If it's already removed the option will be greyed out, which is fine. If you have
multiple layers, do this for all of them. (You MUST remove the alpha channel or else GIMP will write RGBA instead of RGB, and you'll just see a repeating lattice pattern instead of your image.)
File/Save As... and at the very bottom of the save popup, there's an option "Select File Type (By Extension)" with a (+). Expand it.
Select Raw image data
At the top of the save popup, manually give your file a .raw extension and save. Click OK to accept the default options.
Then you should be able to save it, move it to your program's directory, and read it in with the code from that tutorial.
Also, to save yourself another headache source, I suggest adding an error message if the file isn't found, like replace the line
if ( file == NULL ) return 0;
with
if ( file == NULL ){
printf("texture file not found.");
return 0;
}