Problem set 1 solution.

This thing is in Java 1.1, so, IE4 should work. Netscape chokes. Load the image (file name or a URL), set the brush size to whatever you want, pick a color and paint. All the checkboxes apply to the transform back from Freq to spatial domain, so don't bother clicking them when doing forward FFT. There are a few images available that you can get by name: gear.gif, blank.gif, lena.jpg and baboon.jpg

Checkboxes:

• M/C - checkbox selectes Blend(on) or Cutoff(off) filter. When blending, you paint the corresponding frequency component with selected color. When cutting off, everything that you haven't painted will be cut off. White color in the blending mode will have no effect, obviously. Same for Black in Cutoff mode.
• S - scales the image to take full 0-255 magnitude range. You might want to do it using the cutoff filter, since the magnitude might be severely degraded.
• M and P - select what to paint - magnitude or phase, both or none (the last one doesn't strike me as a good choice J )