CS430 - S'04
Lecture 04 : 1/27/04

Reading Assignment: 3 Gonzalez/Woods

Today's Topics

• Histogram Specification
• Local Processing
• Image Arithmetic Operations
• Image Logic Operations

"Pay Up or Else!"

• Bit-plane Slicing



• Histogram Equalization

• Use previous lecture links.
• GW:Figure 3.17 & 3.18 is an excellent example.

• Histogram Specification

1. Obtain the histogram of the given image.
2. Use equalization to precompute a mapped level s(k) for each level r(k).
3. Obtain the transformation function G from the specified histogram using equalization.
4. Precompute z(k) for each value s(k).
5. For each pixel in the original image, if the value of that pizel is r(k), map this value to the corresponding level s(k); then map level s(k) into the final level z(k). Use precomputed values for these mappings.
• Specification slides
• Specification pdf

Original image.



Specified histogram and results in GW:Fig 3.22.

• Local Processing

• Local Equalization GW Fig 3.23
• Local Statistics GW Fig 3.26

• Image Logic

• Image Arithmetic