13-08-2012, 02:19 PM
Image Processing Lecture 4
Image Processing .ppt (Size: 2.07 MB / Downloads: 621)
Spatial Domain Methods
In these methods a operation (linear or non-linear) is performed on the pixels in the neighborhood of coordinate (x,y) in the input image F, giving enhanced image F’
Neighborhood can be any shape but generally it is rectangular ( 3x3, 5x5, 9x9 etc)
Grey Scale Manipulation
Simplest form of window (1x1)
Assume input gray scale values are in range [0, L-1] (in 8 bit images L = 256)
Nth root Transformation
Bit-Plane Slicing
To highlight the contribution made to the total image appearance by specific bits.
i.e. Assuming that each pixel is represented by 8 bits, the image is composed of 8 1-bit planes.
Plane 0 contains the least significant bit and plane 7 contains the most significant bit.
Only the higher order bits (top four) contain visually significant data. The other bit planes contribute the more subtle details.
Histogram Matching (or Specification)
Histogram equalization does not allow interactive image enhancement and generates only one result: an approximation to a uniform histogram.
Sometimes though, we need to be able to specify particular histogram shapes capable of highlighting certain gray-level ranges.