Filtering and thresholding

   

This command performs a median and average filtering for the image.

This command converts a gray-scaled picture into black and white using the flag -val as a dividing color value. A negative value switches white and black color use. If a correlation algorithm is used, then the flag -val should be omitted.

This command calculates the average value of the matrix points and moves all values so that the average value becomes zero.

Example (ex6.2):

NDA> load fz_sets.dat 
NDA> loadimg 003.gif ball
...
# histogramming and filtering
NDA> photohisto pict1
NDA> filter -in pict1 -out pict1avg -avg -rad 2
NDA> threshold -in pict1 -out pict1thresh -corr
NDA> histoeq -in pict1 -out pict1heq
# convert images to the matrix
NDA> convmatrix -in pict1 -out pict1matr
NDA> balance -in pict1matr.real -out pict1matrbal.real
NDA> convmatrix -in pict1avg -out pict1avgmatr
NDA> convmatrix -in pict1heq -out pict1heqmatr
...