Image Processing

Report #3

 

The magnitude representation of the FFT
 
Original Magnitude of fft
 
This is the magnitude representation of the fft of the image lenna.  Within this image a noticeable vertical line appears
This line may be due to the horizontal edges found within lenna.  This fft was scaled using range compression.
Without the use of range compression the image is basically all black.
 

Low pass results
 
Original LowPass( filter is picked close to center ) LowPass( filter is picked closer to the edge of image )
 
Low pass filtering is good for smoothing images.  However if one gets closer the maximum impulse response the smoother the image gets as noticed from the middle
image.  If one gets further away the smoothing is not as rampant.
 

 

High pass results
 
Original High pass
 
High pass filtering is useful in stretching edges and sharpening the image.  I believe I was further away from the impulse max and hence the
image got rather dark.
 

Subimage results
 

part of the report

Original subImage
 
One can also take part of an image, fft it , and put back to combine the image into one.