In this project, I wrote a few simple C programs and familarize myself with Unix, C and the mechanics of creating, manipulating, and writing images.
Turning a picture blue
I modified the code in ppmmain.c to turn a picture blue by setting the red and green channels to 0.
Blue screen detection
My function bluescreen creates a mask from a image taken with a blue screen background, by using the comparison blue > 2*red and blue > green.
My blending function takes in a background and a foreground image. The foreground image has to be taken in blue screen. The blend function then creates a mask from the bluescreen image and blend the two image together.
I wrote a scaledown function that takes in a scale factor and scales the image down. Then I used my blending function to blend the scaled picture into the background.