Illuminate image.
The operator illuminate__ enhances contrast. Very dark parts of the image are "illuminated" more strongly, very light ones are "darkened". If orig is the original gray value and mean is the corresponding gray value of the low pass filtered image detected via the operators mean__ and filter size MaskHeight x MaskWidth, the resulting gray value is new:
new = round ( (127 - low) * Factor + orig ).
Height Width Factor --------------------- 40 40 0.55 100 100 0.7 150 150 0.8The following "spotlight effect" should be noted: If, for example, a dark object is in front of a light wall the object as well as the wall, which is already light in the immediate proximity of the object contours, are lightened by the operator illuminate__. This corresponds roughly to the effect that is produced when the object is illuminated by a strong spotlight. The same applies to light objects in front of a darker background. In this case, however, the fictitious "spotlight" darkens objects.
attention.english
Image (input_object) |
image(-array) -> object : byte |
Image to be enhanced. |
ImageIlluminate (output_object) |
image(-array) -> object : byte |
"Illuminated" image. |
MaskWidth (input_control) |
extent.x -> integer |
Width of low pass mask. | |
Default value: 101 | |
Suggested values: 31, 41, 51, 71, 101, 121, 151, 201 | |
Range of values: 3 <= MaskWidth <= 299 | |
Minimum increment: 2 | |
Recommended increment: 10 |
MaskHeight (input_control) |
extent.y -> integer |
Height of low pass mask. | |
Default value: 101 | |
Suggested values: 31, 41, 51, 71, 101, 121, 151, 201 | |
Range of values: 3 <= MaskHeight <= 299 | |
Minimum increment: 2 | |
Recommended increment: 10 |
Factor (input_control) |
real -> real |
Scales the "correction gray value" added to the original gray values. | |
Default value: 0.7 | |
Suggested values: 0.3, 0.5, 0.7, 1.0, 1.5, 2.0, 3.0, 5.0 | |
Range of values: 0.0 <= Factor <= 5.0 | |
Minimum increment: 0.01 | |
Recommended increment: 0.2 | |
Restriction: (0 < Factor) && (Factor < 5) |
read_image(:Image:'fabrik':) > disp_image(Image:::) illuminate__(Image:Better:40,40,0.55:) > disp_image(Better:::).
If the parameter values are correct the operator illuminate__ 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.
scale_max, equ_histo__, mean__, sub__