Crop out unwanted part from an image.

2 次查看（过去 30 天）
Pramod Bhat
Pramod Bhat 2011-11-15
Dear friends, I want to crop out extra part of CT Head image. I mean i want my image should have only required part of the image by removing unwanted black background.
  1 个评论
Sven
Sven 2011-11-15
So you have a single 2D image?
Let's say you want to remove the top and bottom 5 rows and the first 10 columns:
originalIm = rand(512,512);
croppedIm = originalIm(6:end-5, 11:end);
If this *doesn't* answer your question, please realise that you need to make your question more specific.

请先登录，再进行评论。

请先登录，再回答此问题。

回答（2 个）

Walter Roberson
Walter Roberson 2011-11-15
Threshold the image so that the "black" background values are assigned 0. Suppose we refer to that result as ImThr . Then
foregroundcol = any(ImThr);
firstforegroundcol = find(foregroundcol, 1);
lastforegroundcol = find(foregroundcol, 1, 'last');
foregroundrow = any(ImThr,2);
firstforegroundrow = find(foregroundrow, 1);
lastforegroundrow = find(foregroundrow, 1, 'last');
And then we can extract the foreground from the frame:
foregroundImg = OriginalImg(firstforegroundrow:lastforegroundrow, firstforegroundcol:lastforegroundcol);
Note that this construction assumes there is no outline or annotations around the image, just image.
Image Analyst
Image Analyst 2011-11-15
See my BlobsDemo: http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862
It does exactly this with the standard coins image, assuming you can determine foreground and background solely by intensity thresholding.

类别

在 Help Center 和 File Exchange 中查找有关 Get Started with MATLAB 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by