PPA Ridge Picker Paper Download: PDF, DOI
Download Program: Source Code , Install Files, Executable File Only
Examples of DEM input file: 100x100, 200x200
Program Description:
This is a Visual Basic 6.0 Ridge-Picking program based on PPA method. The program was designed purposely for demonstration of the operation process of PPA method. So, it is not as fast as it can. If you want to apply this method to any pratical purpose, you are welcome to contach with me. I am very interested to implement PPA for more diffeent uses.
To execute the program, please follow the steps below:
1. Select Function [File] => [Open File] and select the example file, or file with the same format
* A gray image will appear.
2. Select Function [Execute] => [Segmentation]
* A group of yellow "firm" ridge segments will appear first, then the other possible ridge segments in red color will appear.
3. Select Function [Execute] => [Polygon Breaking]
* Many segments will be checked out one by one, if they are the lowest side of any closed polygon.
4. Select Function [Execute] => [Branch Reduction]
* The tail of branches will shrink to a "firm" segment. Only the well-defined "firm" segment can be the end of any branch tail.
5. Select Function [Execute] => [Reduction in length]
* A selection frame will guide you to choose a threshold of branch length, any branch shorter than that will be eliminated.
Other Functions:
1. The Profile Recognition Length can be changed by [Option] => [Profile Length]
2. The map size shown can be adjusted by [Option] => [Zoom Factor]
3. If the map larger than the viewable range of screen, the map can be dragged to move like normal windows.
4. The image can be saved in any stage using [File] => [Save Image]
5. The Segments can also be saved using [File] => [Save Segments]
6. The elevation of each point can be checked by putting mouse cursor on it.
Gray Level Map (Step 1)
Segment Map (Step 2)
Polygon Breaking Map, green chain show the route checking... (Step 3)
Branches cleaned (Step 4)
