SPATIAL_QUANT_CVIP

spatial_quant_cvip() - Reduces the image size using spatial quantization method.

SYNTAX
DESCRIPTION
REFERENCE
EXAMPLE
CREDITS

SYNTAX

outImage = spatial_quant_cvip( inImage, row, col, method)

Input Parameters include :

inImage - Input image of MxN or MxNxB size. The input image can be of uint8 or uint16 or double class.
row - Number of rows or height(1 < row <= M). ( M | default)
col - Number of columns or width (1 < col <= N). ( N | default)
method - Reduction method.

                   method = 1 ---> average

                   method = 2 ---> median

                   method = 3 ---> decimation

                   method = 4 ---> maximum

                   method = 5 ---> minimum

                  ( 1 | default)

Output Parameter includes :

outImage - Spatial quant image

DESCRIPTION

The function performs spatial quantization using five reduction methods. spatial_quant allows the user to specify the number of rows and columns in the resultant image, corresponding to the height and width of the new image. The integers specified for row and column sizes must be equal to or less than the input image sizes or an error results. Three methods are available for image reduction: 1) AVERAGE - each pixel in the new image represents an average of the original image pixels it replaces. 2) MEDIAN - each pixel in the new image represents the median value of the original image pixels it replaces. 3) DECIMATION - each pixel in the new image has the same value as a corresponding pixel in the original image; other original-image pixels are discarded. 4) MAXIMUM - each pixel in the new image represents the maximum value of the original image pixels it replaces. 5) MINIMUM - each pixel in the new image represents the minimum value of the original image pixels it replaces.

Because the user may enter different values for height and width, spatial_quant may be used to geometrically distort the image in a rubber-sheet fashion.

REFERENCE

1. Scott E Umbaugh. DIGITAL IMAGE PROCESSING AND ANALYSIS: Applications with MATLAB and CVIPtools, 3rd Edition.

EXAMPLE

% Read image

 I = imread('cam.bmp');

% Perform spatial quantization with default method

 O1 = spatial_quant_cvip(I, 200, 200,1);

% Perform spatial quantization with user specified parameters

 O2 = spatial_quant_cvip(I, 180, 200, 3);

% Display input image

 figure;imshow(I);title('Input Image');

% Display output image

 figure; imshow(hist_stretch_cvip(O1,0,1,0,0));title('Output Image with default parameters');

 figure; imshow(hist_stretch_cvip(O2,0,1,0,0));title('Output Image with user specified parameters');

SPATIAL_QUANT_CVIP

Contents

SYNTAX

DESCRIPTION

REFERENCE

EXAMPLE

CREDITS