emphasize__ ( Image : ImageEmphasize : MaskWidth, MaskHeight, Factor : )

Enhance contrast of the image.

The operator emphasize__ emphasizes high frequency areas of the image (edges and corners). The resulting images appears sharper.

First the procedure carries out a filtering with the low pass (mean__). The resulting gray values (res) are calculated from the obtained gray values (mean) and the original gray values (orig) as follows: res := round((orig - mean) * Factor) + orig


Attention

attention.english


Parameters

Image (input_object)
image(-array) -> object : byte
Image to be enhanced.

ImageEmphasize (output_object)
image(-array) -> object : byte
contrast enhanced image.

MaskWidth (input_control)
extent.x -> integer
Width of low pass mask.
Default value: 7
Suggested values: 3, 5, 7, 9, 11, 15, 21, 25, 31, 39
Range of values: 3 <= MaskWidth <= 201
Minimum increment: 2
Recommended increment: 2

MaskHeight (input_control)
extent.y -> integer
Height of the low pass mask.
Default value: 7
Suggested values: 3, 5, 7, 9, 11, 15, 21, 25, 31, 39
Range of values: 3 <= MaskHeight <= 201
Minimum increment: 2
Recommended increment: 2

Factor (input_control)
real -> real
Intensity of contrast emphasis.
Default value: 1.0
Suggested values: 0.3, 0.5, 0.7, 1.0, 1.4, 1.8, 2.0
Range of values: 0.0 <= Factor <= 20.0 (sqrt)
Minimum increment: 0.01
Recommended increment: 0.2
Restriction: (0 < Factor) && (Factor < 20)


Example
read_image(:Image:'meer_rot':) >
disp_image(Image:::) >
draw_region(:Region::) >
reduce_domain(Image,Region:Mask::) >
emphasize__(Mask:Sharp:7,7,2.0) >
disp_image(Sharp:::).

Result

If the parameter values are correct the operator emphasize__ returns the value TRUE The behavior in case of empty input (no input images available) is set via the operator set_system(::'no_object_result',<Result>:). If necessary an exception is raised.


Possible Successors

disp_image


Alternatives

mean__, sub__, laplace__, add__


See also

mean__, highpass__



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