mean_sp — Suppress salt and pepper noise.
mean_sp(Image : ImageSPMean : MaskWidth, MaskHeight, MinThresh, MaxThresh : )
The operator mean_sp carries out a smoothing by
averaging the values. Only the gray values within the interval from
MinThresh to MaxThresh are averaged. Gray
values which are too light or too dark are ignored during summation.
If no gray value lies within the default interval during summation
the original gray value is adopted. If the thresholds are set at
0 or 255, respectively, the operator
mean_sp behaves like mean_image except for the
running time.
The operator mean_sp is used to suppress extreme gray
values (salt and pepper noise = white and black dots).
For an explanation of the concept of smoothing filters see the introduction of chapter Filters / Smoothing.
If even values instead of odd values are given for
MaskHeight or MaskWidth, the routine uses the
next larger odd values instead (this way the center of the filter
mask is always explicitly determined).
This operator may return unexpected results if an image with a reduced domain is used as input. Please refer to the chapter Filters.
Image (input_object) (multichannel-)image(-array) → object (byte / uint2)
Input image.
ImageSPMean (output_object) (multichannel-)image(-array) → object (byte / uint2)
Smoothed image.
MaskWidth (input_control) extent.x → (integer)
Width of filter mask.
Default value: 3
Suggested values: 3, 5, 7, 9, 11
Typical range of values: 3
≤
MaskWidth
≤
512 (lin)
Minimum increment: 2
Recommended increment: 2
Restriction: odd(MaskWidth) && MaskWidth < width(Image) * 2
MaskHeight (input_control) extent.y → (integer)
Height of filter mask.
Default value: 3
Suggested values: 3, 5, 7, 9, 11
Typical range of values: 3
≤
MaskHeight
≤
512 (lin)
Minimum increment: 2
Recommended increment: 2
Restriction: odd(MaskHeight) && MaskHeight < height(Image) * 2
MinThresh (input_control) integer → (integer)
Minimum gray value.
Default value: 1
Suggested values: 1, 5, 7, 9, 11, 15, 23, 31, 43, 61, 101
MaxThresh (input_control) integer → (integer)
Maximum gray value.
Default value: 254
Suggested values: 5, 7, 9, 11, 15, 23, 31, 43, 61, 101, 200, 230, 250, 254
Restriction: MinThresh <= MaxThresh
read_image(Image,'mreut') dev_display(Image) mean_sp(Image,ImageMeansp,3,3,101,201) dev_display(ImageMeansp)
mean_image,
median_image,
median_separate,
eliminate_min_max
anisotropic_diffusion,
sigma_image,
binomial_filter,
gauss_filter,
smooth_image,
eliminate_min_max
Foundation