MATLAB: How to find slope of many line on this picture with noise

average slopeImage Processing Toolboxlinearmanylineransacslopeslope many line

i need to find average slope of many line ? (sorry for my English)

Best Answer

A pure imaging approach, though probably not as good as RANSAC, would be to try to join the lines with imclose(), then label and call regionprops asking for the orientation:

binaryImage = grayImage < someThreshold; % or however.....
[labeledImage, numBlobs] = bwlabel(binaryImage);
props = regionprops(labeledImage, 'Orientation');
allAngles = [props.Orientation];

Some of the short lines that are on the same "line" but far away would be detected as their own independent line rather than being two distant, well separated parts of the same line.

Related Solutions

MATLAB: How to get all the orientation of the lines in a 2-D image

Use regionprops(). Something like

binaryImage = grayImage < 220;
props = regionprops(binaryImage, 'Orientation');
allAngles = [props.Orientation];

Let us know if you need a full demo, and if so, attach your full size image.

MATLAB: How to color an image according to orientation of objects

When you regionprops(), also ask for PixelIdxList .

Now, create a matrix

orient = zeros(size(BW));

And loop through the struct array you got from regionprops:

orient(props(K).PixelIdxList) = props(K).orientation;

After this you can imshow() or imagesc() orient .

Note that very high orientations and very low orientations are close to each other, so you might want to use an hsv colormap or something similar that is "circular"

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Related Solutions

MATLAB: How to get all the orientation of the lines in a 2-D image

MATLAB: How to color an image according to orientation of objects

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