How to remove a percentage of image counting from the bottom to top

4 次查看（过去 30 天）
Stelios Fanourakis
Stelios Fanourakis 2019-1-30
评论： Stelios Fanourakis 2019-1-30
Hi
I want to subtract a portion of image (e.g. 30% of it from the top). How do I do that?
If I do, something like this,
img = (croppedImage - (croppedImage.*0.3));
I usually get a 30% deduction from the bottom of it. I want this deduction to be from the top.
Moreover, I need a method to translate the deduction to number of rows. To be known, how many pixel rows this 30% of the image is.
Any ideas please?

请先登录，再回答此问题。

采纳的回答

Mark Sherstan
Mark Sherstan 2019-1-30
编辑：Mark Sherstan 2019-1-30
Look at the example I wrote for you below. Use the size function and realize that imcrop takes an array in the form of [xPosition yPosition width height] where the (0,0) point is the top left corner of your image.
I = imread('test.png');
[height width dims] = size(I);
J = imcrop(I,[0 floor(height*0.3) width height-floor(height*0.3)]);
figure(1)
subplot(1,2,1); imshow(I)
subplot(1,2,2); imshow(J)
  3 个评论
显示 1更早的评论
Mark Sherstan
Mark Sherstan 2019-1-30
Glad it worked! You could do something along the lines of this:
I = imread('test.png');
[height width dims] = size(I);
rows30 = floor(height*0.3) % I used floor but you can use ceil, round, etc...

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Image Processing Toolbox 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