Define a curve in terms of (X,Y) values

1 次查看（过去 30 天）
Ashkan Javadzadegan
评论： Ashkan Javadzadegan 2015-4-16
Dear all,
I detected an artery borderline (Image B) on a grayscale image (image A). Now I would like to define the detected borderline in terms of (X,Y) values.
Would be much appreciated if any body could give me a hint. Ashkan

请先登录，再回答此问题。

回答（1 个）

pfb
pfb 2015-4-15
I assume that B is in a single matrix. The light point should then correspond to matrix elements above some threshold. If this is the case, it should be sufficient to do this
[y x] = find(B>t);
  5 个评论
显示 3更早的评论
pfb
pfb 2015-4-15
编辑：pfb 2015-4-16
Well, that should not be that hard.
[Y,X] = size(B);
Gives you the size of the image in the vertical and horizontal direction (in pixels). You should know what that is in mm.
The "origin" is then
o = [X/2 Y/2];
Use round() if your matrix has odd dimensions and you want integer numbers.
Then
x = x-o;
y = y-o;
Again, these coordinates are "in pixels", but if you know the scale of the image it is easy to get the correct values. If Sx and Sy are the dimensions of the image in mms then
x = Sx/X*x;
y = Sy/Y*y;
Why your 3D model design software should care about where the origin of the axes is?
Ashkan Javadzadegan
Ashkan Javadzadegan 2015-4-16
Thanks, I will try this and will let you know ...

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Image Segmentation and Analysis 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