This preview shows pages 1–2. Sign up to view the full content.
HW2
Image Enhancement Using Filtering
Prob. 1 (20 %)
Image graylevel stretching.
Read in the HW_2_1.jpg image and display the image and comment on its brightness
and contrast.
a)
Plot a histogram of the image. Although Matlab has a histogram function, write
your own code to calculate the histogram. What are the mean and standard
deviation of this image?
b)
Compute the mean and standard deviation of the gray levels of this image.
c)
Derive a transformation that yields a mean of 128 and a standard deviation of 80
for the processed image. Stretch the image according to your transformation and
display it. Make sure you account for pixels falling "off the ends" of the
distribution (i.e., less than 0 and greater than 255). Submit the processed image,
and also a plot of the new histogram.
Prob. 2 (20 %)
Powerlaw transformation
Based on the low contrast image HW_2_1.jpg, please use the powerlaw transform, i.e.,
cr
s
, to enhance the image. First, you have to decide the value of power
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 07/08/2011 for the course EE 440 taught by Professor Jenqnenghwang during the Spring '11 term at University of Washington.
 Spring '11
 JenqNengHwang

Click to edit the document details