| filter | Perform a median and average filtering for an image |
| -in <image> | image to be filtered |
| -out <image> | output image |
| -avg | average filtering |
| -med | median filtering |
| [-rad <n>] | radius (in pixels) of the filtering mask (default 1) |
This command performs a median and/or average filtering for the image.
| threshold | Convert a grayscale picture into black and white |
| -in <image> | input image |
| -out <image> | resulting image |
| -val <n> | limit as integer (signed) |
| [-corr] | use correlation method for thresholding |
This command converts a grayscale picture into black and white using the value specified with flag -val as a dividing gray level. A negative value switches white and black color use and the absolute value is used in thresholding. If the correlation algorithm is used, then flag -val should be omitted.
| balance | Calculate the average value of matrix points and balance them |
| -in <matrix> | a two-dimensional input matrix |
| -out <matrix> | output matrix |
This command calculates the average value of matrix points and changes all values in such a manner that the average value becomes zero.
| negative | Convert grayscale image into negative |
| -in <image> | input image |
| -out <image> | output image |
This command inverts the specified image into a negative.
Example (ex6.2):
NDA> load fz_sets.dat NDA> loadimg i003.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 into matrix form 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 ...