EE4206/EE5806 Digital Image Processing

EE4206/EE5806 Digital Image Processing

Point Operations 強烈譴責中共六四屠殺

quoted from Digital Image Processing : An algorithmic Introduction Using Java by Burger and Burge (2008) page : 53-55

Point operations perform a mapping of the pixel values without changing the size, geometry or local structure of the image.

Each new pixel value a'=I'(u,v) depends exclusively on the previous value a = I(u,v) at the SAME position and is thus independent from any other value, in particular from any of its neighboring pixels.

2. If the function f() is independent of the image coordinates (ie, the same through the image), the operation is called "homogeneous".

3. Inverting Images : Inverting an intensity image is that reverses the ordering of pixel values ( by multiplying with -1 ) and adds a constant value to map the result to the admissible range again.

4. Threshold operation : Thresholding an image is a special type of quantization that separates the pixel values in TWO classes, depending upon a given threshold value a-th. To binarize an intensity image with the values a0=0 and a1=1.