Name
topographic_sketchtopographic_sketchTopographicSketchtopographic_sketchTopographicSketchTopographicSketch — Compute the topographic primal sketch of an image.
Herror topographic_sketch(const Hobject Image, Hobject* Sketch)
Herror T_topographic_sketch(const Hobject Image, Hobject* Sketch)
topographic_sketchtopographic_sketchTopographicSketchtopographic_sketchTopographicSketchTopographicSketch computes the topographic primal
sketch of the input image ImageImageImageImageImageimage. This is done by
approximating the image locally by a bicubic polynomial (“facet
model”). It serves to calculate the first and second partial
derivatives of the image, and thus to classify the image into 11
classes. These classes are coded in the output image
SketchSketchSketchSketchSketchsketch as numbers from 1 to 11. The classes are as
follows:
Peak |
1 |
Pit |
2 |
Ridge |
3 |
Ravine |
4 |
Saddle |
5 |
Flat |
6 |
Hillside Slope |
7 |
Hillside Convex |
8 |
Hillside Concave |
9 |
Hillside Saddle |
10 |
Hillside Inflection |
11
|
In order to obtain the separate classes as regions, a threshold
operation has to be applied to the result image with the appropriate
thresholds.
- Multithreading type: reentrant (runs in parallel with non-exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Automatically parallelized on tuple level.
- Automatically parallelized on channel level.
Image for which the topographic primal sketch
is to be computed.
Label image containing the 11 classes.
* To extract the Ridges from a Image
read_image(Image,'sinus')
topographic_sketch(Image,Sketch)
threshold(Sketch,Ridges,3,3)
/* To extract the Ridges from a Image */
read_image(&Image,"sinus");
topographic_sketch(Image,&Sketch);
threshold(Sketch,&Ridges,3.0,3.0);
* To extract the Ridges from a Image
read_image(Image,'sinus')
topographic_sketch(Image,Sketch)
threshold(Sketch,Ridges,3,3)
* To extract the Ridges from a Image
read_image(Image,'sinus')
topographic_sketch(Image,Sketch)
threshold(Sketch,Ridges,3,3)
* To extract the Ridges from a Image
read_image(Image,'sinus')
topographic_sketch(Image,Sketch)
threshold(Sketch,Ridges,3,3)
* To extract the Ridges from a Image
read_image(Image,'sinus')
topographic_sketch(Image,Sketch)
threshold(Sketch,Ridges,3,3)
Let n be the number of pixels in the image. Then O(n)
operations are performed.
topographic_sketchtopographic_sketchTopographicSketchtopographic_sketchTopographicSketchTopographicSketch returns 2 (H_MSG_TRUE) if all parameters are
correct. If the input is empty the behavior can be set via
set_system('no_object_result',<Result>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>).
If necessary, an exception is raised.
thresholdthresholdThresholdthresholdThresholdThreshold
R. Haralick, L. Shapiro: “Computer and Robot Vision, Volume I”;
Reading, Massachusetts, Addison-Wesley; 1992; Kapitel 8.13.
Foundation