how to draw a free hand box on an image to select that region of interest?

5 次查看（过去 30 天）
Manoj Kumar
Manoj Kumar 2014-12-22
评论： Sean de Wolski 2015-1-27
hi,
I used this for free hand drawing in an irregular shape. But I need to draw a box to select a region.
% Get the input free hand image
figure, imshow(grayImage, []);
axis on;
title('Contour Region Required', 'FontSize', fontSize);
set(gcf, 'Position', get(0,'Screensize')); % Maximize figure.
message = sprintf('Left click and hold to begin drawing.\nRelease Mouse Button when Completed');
uiwait(msgbox(message));
hFH = imfreehand();
% Create a binary image ("mask") from the ROI object.
binaryImage = hFH.createMask();
xy = hFH.getPosition;
% Label the binary image and compute the centroid and center of mass.
labeledImage = bwlabel(binaryImage);
% Will keep only the part of the image that's inside the mask, zero outside mask.
blackMaskedImage = grayImage;
blackMaskedImage(~binaryImage) = 0;
Can you please suggest me free hand drawing a box.
Thanks...

请先登录，再回答此问题。

采纳的回答

Sean de Wolski
Sean de Wolski 2014-12-22
To force it to a rectangle, use imrect which has the same api as imfreehand.
  3 个评论
显示 1更早的评论
Manoj Kumar
Manoj Kumar 2015-1-27
Is there any way that after drawing the box, Can i rotate it ( I mean can I perform any orientation to the box)?
Sean de Wolski
Sean de Wolski 2015-1-27
Not easily. You would have to build a second impoly and then manually transform its vertices.

请先登录，再进行评论。

更多回答（2 个）

Chad Greene
Chad Greene 2014-12-22
If you have the Image Processing Toolbox, http://www.mathworks.com/help/images/ref/imfreehand.html
Image Analyst
Image Analyst 2014-12-22
If you don't have the Image Processing Toolbox, you can use rbbox():
k = waitforbuttonpress;
point1 = get(gca,'CurrentPoint'); % button down detected
finalRect = rbbox; % return figure units
point2 = get(gca,'CurrentPoint'); % button up detected
point1 = point1(1,1:2); % extract x and y
point2 = point2(1,1:2);
p1 = min(point1,point2); % calculate locations
offset = abs(point1-point2); % and dimensions
% Find the coordinates of the box.
xCoords = [p1(1) p1(1)+offset(1) p1(1)+offset(1) p1(1) p1(1)];
yCoords = [p1(2) p1(2) p1(2)+offset(2) p1(2)+offset(2) p1(2)];
x1 = round(xCoords(1));
x2 = round(xCoords(2));
y1 = round(yCoords(5));
y2 = round(yCoords(3));
hold on
plot(xCoords, yCoords, 'b-'); % redraw in dataspace units
  2 个评论
Manoj Kumar
Manoj Kumar 2014-12-24
Then how to get the coordinates of the two points that I use to make a rectange using imrect()?
Image Analyst
Image Analyst 2014-12-24
Did you overlook how I get x1,x2,y1,y2?
And you don't use imrect anymore - this is used in place of it. One advantage is that you just drag out a box and you're done. It doesn't let you adjust the size (of course you could put it in a loop where you redraw it) but you don't have the extra step of having to double-click inside the box (which is confusing to users - they won't know to do that unless you give them instructions in advance).

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Geometric Transformation and Image Registration 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