Edge Detection and Image Segmentation (EDISON) System

Table of Contents

- Introduction
- System Overview
- Confidence Based Edge Detector
- Mean Shift Based Image Segmenter
- Synergistic Image Segmenter
- References

##### Confidence Based Edge Detector

This program implements the edge detection algorithm described in [2].

Usage instructions:

- From the File menu select Load image to select and load an image (known formats: PNG, BMP, GIF, TIFF, JPEG, PNM, PGM, PPM).
- To apply the edge detection algorithm on the image, from the Edge Detect menu select Edge Detect or simply press the Edge Detect button located in the upper left hand corner of the current edge detection frame. The detected edges are shown superimposed over the original image. The original image and detected edges are displayed when the View Image and View Edges checkboxes, located on the left of the current edge detection frame, are marked.
- To save the edge map generated by the edge detection algorithm as a PGM file, from the File menu select Save Edge Map.

The gradient rank-confidence space before non-maxima suppression is displayed in the lower right panel of the current edge frame. The curve used for non-maxima suppression is displayed within this frame. The same space after non-maxima suppression is displayed in the upper right panel of the current edge detection frame. The curves for hysteresis thresholding (blue - high curve, red - low curve) are displayed within this frame.

The shape and location of each curve may be modified. To change the location of a curve select it and drag it with the mouse to the new location. To change the shape of a curve right click the desired curve and select the desired shape from the drop down menu.

One option displayed in this menu allows for the definition of a custom shape. To create a custom shape, first add or delete nodes from the curve by right clicking the mouse over the desired node location on the curve and selecting either Add Node or Delete Node from the drop down menu. Then drag these nodes to their respective locations to form the desired custom curve.

The parameters generated by the above curves may also be entered manually. To do so, from the Edge Detect menu select Change Parameters or click on the Parameters button located on the left of the current edge detection frame. This option also allows for changing the filter size and the minimum number of pixels on an edge.

NOTE: After changing the parameters the edge map is not automatically updated, you must run the algorithm again to see the result.

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Robust Image Understanding Lab, (freeware) 2002