Split image using a predefined line
显示 更早的评论
Is there anyway to split an image into two using a predefined line that passes through an object's centroid. I have already found the centroid and plotted the line, but I am unsure of how to separate the image using this line. Many Thanks
2 个评论
Ben
2014-5-2
编辑：Image Analyst
2014-5-2
I have drawn this line, and i wish to separate the image so i can calculate the height and width of both the bottom and top sections. The image doesn't need to be physically separated, just recognised as two different objects
采纳的回答
Image Analyst
2014-5-2
Sure. I'm going to assume the line cuts across the entire image. Then use poly2mask() to create a binary image.
mask = poly2mask(x, y);
Then you can either blacken above/below the line.
imageAbove = grayImage;
imageAbove(mask) = 0;
imageBelow = grayImage;
imageBelow(~mask) = 0;
You can also crop to the bounding box or leave it at the original size, using imcrop() or regular indexing.
5 个评论
Image Analyst
2014-5-2
You need to extend the line from the centroid, at whatever angle it is, until each end strikes the boundary of the image. Then add points at the corners of the image. So you will have either 3, 4, or 5 vertices depending on exactly where the line strikes the outer perimeter of your image.
Image Analyst
2014-5-2
If the line is horizontal, just use normal, regular indexing:
topPart = grayImage(1:middleRow,:);
bottomPart = grayImage(middleRow+1:end, :);
Image Analyst
2014-5-3
Ben, it's just simple algebra. I simply used the point slope formula for a line. See attached test3.m file to produce the image below.
更多回答（0 个）
类别
在 帮助中心 和 File Exchange 中查找有关 Image Arithmetic 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
