Name | Synopsis | Description | Parameters | Return Values | Attributes | See Also
cc [ flag... ] file... -lmlib [ library... ] #include <mlib.h> mlib_status mlib_ImageStdDev(mlib_d64 *sdev, const mlib_image *img, const mlib_d64 *mean);
The mlib_ImageStdDev() function computes the standard deviation for each channel in the source image.
It uses the following equation:
1 w-1 h-1 sdev[i] = { ----- * SUM SUM (img[x][y][i] - mean[i])**2 }**0.5 w*h x=0 y=0
where, in the case of mean == NULL,
1 w-1 h-1 mean[i] = ----- * SUM SUM img[x][y][i] w*h x=0 y=0
The function takes the following arguments:
Pointer to standard deviation array, whose size is the number of channels in the source image. sdev[i] contains the standard deviation of channel i.
Pointer to input image.
Pointer to pre-computed mean array for each channel. (If NULL, it will be computed.) mean[i] contains the mean of channel i.
The function returns MLIB_SUCCESS if successful. Otherwise it returns MLIB_FAILURE.
See attributes(5) for descriptions of the following attributes:
ATTRIBUTE TYPE |
ATTRIBUTE VALUE |
---|---|
Interface Stability |
Committed |
MT-Level |
MT-Safe |
Name | Synopsis | Description | Parameters | Return Values | Attributes | See Also