Works the following way:
- Convert the canvas image to grayscale
- Smooth the image to reduce noise as much as possible. In this implementation, Gaussian filter can be applied (max kernel size is 21).
- Determine the gradient intensity (amount of change) and direction for each pixel. This is done by convolving image with the chosen filter. Currently, there are 3 operators you may choose from:
- Sobel
- Prewitts
- Cross
- Thin the resulting edges with non-maximum suppression.
- Remove weak/false edges. A process called hysteresis is used where there are two thresholds--high and low--to be compared to each pixel.
You'll need Node.js installed. Go to root directory of the project and start by entering the following on your terminal:
node js/server.js
Access program on port 8000.
- Cleanup image uploading.
- Fix non-maximum suppression thresholding (especially bad with Cross filter)
- Add other filters
- @Tagussan: Otsu's method for thresholding.
Distributed under the terms of the GNU General Public License version 3.
Copyright (C) 2013 cmisenas
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see http://www.gnu.org/licenses/.