How to plot a circular Image?

2014 7 21
2 个回答
回答已采纳
更新时间：2014 7 21
6 次查看（30 天）

0 个投票

I want to plot a binary image like this:
However, I only want the red region to be shown in the figure.How can I do this?
tnx in advance

1 个评论
显示 -1更早的评论 隐藏 -1更早的评论

Geoff Hayes
Geoff Hayes 2014-7-21
Ramin - what exactly are your inputs to draw the above? Do you determine the radius of the red circle? Do you decide on the number of solid black balls that fill the red region? Do you decide on the radius of each solid black ball?

请先登录，再进行评论。

请先登录，再回答此问题。

 采纳的回答

Image Analyst
Image Analyst 2014-7-21

1 个投票

You can draw only the red circle by using rectangle().
For other approaches to drawing circles, see the FAQ on circles, or see my attached demos.

更多回答（1 个）

Robert Cumming
Robert Cumming 2014-7-21

0 个投票

A couple of options for you:
% First create an axes and some data:
ax = axes;
ang=0:0.01:2*pi;
xp=1*cos(ang);
yp=1*sin(ang);
patch ( xp, yp, 'w', 'parent', ax )
axis ( ax, 'equal' )
% option 1 - hide the axes to leave your image:
set ( ax, 'visible', 'off' )
% option 2 - set the background of your image to be the same as the parent:
set ( ax, 'color', get ( get ( ax, 'parent' ), 'color' ) )

2 个评论
显示 无 隐藏 无

ramin bba
ramin bba 2014-7-21
thanks Robert. A question:
should I use the above after I have read my image? 'cause it is not working properly! it actually puts a disk on my current image and hides a circular portion of it! here is what I do:
a=imread('...');
imshow(a);
ax = axes;
ang=0:0.01:2*pi;
xp=1*cos(ang);
yp=1*sin(ang);
patch ( xp, yp, 'w', 'parent', ax )
axis ( ax, 'equal' )
set ( ax, 'color', get ( get ( ax, 'parent' ), 'color' ) )
Robert Cumming
Robert Cumming 2014-7-21
My example draws a circle as an example. You would need to remove that part. You only need the last part which hides the axes, or changes the background colour.

请先登录，再进行评论。

类别

在 帮助中心 和 File Exchange 中查找有关 Surface and Mesh Plots 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