User`s guide

Feature Extraction
17 Run your model again.
Your model runs faster because the Edge D etection block is more efficient
when you clear the Edge thinning check box. However, the edges of rice
grains in the Video Viewer window are wider.
You have now used the Edge Detection block to find the object boundaries in
an image. For more inform ation on this block, see the Edge Detection block
reference page in the Video and Image Processing Blockset Reference.
Finding Lines in Images
Finding lines within images enables you to detect, measure, and recognize
objects. In this section, you use the Hough Transform, Find Lo cal Maxima,
andHoughLinesblockstofindthelongestlineinanimage.
1 Define an intensity image in the MATLAB workspace. At the MATLAB
command prompt, type
I= imread('circuit.tif');
I is a 280-by-272 matrix of 8-bit unsigned integers.
2 To view the image, at the MATLAB com m and prom pt, type
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