Biomedical Imaging Group
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Edge Detector


Edge detection is a fundamental operation in image processing. We propose here an efficient and fast method similar to the Canny-Deriche edge operator. There are five steps following the diagram:

  1. Smoothing: using a gaussian smoothing operator

  2. Gradient

  3. Non-maximum suppression

  4. Hysteresis threshold


Instruction to use the applet
  1. Choose an input image in the list.
    You can upload your own image into the applet.
    Choose your image file and click on the button "Launch Demo".
    The applet accepts GIF or JPEG 256*256 pixels image (max size 1 Mb).
  2. Choose the parameters.
  3. Press on "Run All steps" button to run all the steps or "Step" button to process step by step
Toolbar in the image display
pointer_on Get the coordinates and value of a pixel.
info_on Get the maximum, minimum and the mean value of the image.
frame Open a new window containing the image.
zoomin_on Zoom out by a factor 2.
(N/A on Netscape)
zoomout_on Zoom in by a factor 2. (N/A on Netscape)
move Move the zoomed part of the image. (N/A on Netscape)