add cropOrientedBox.m

Author: dlegland

src/@Image/cropOrientedBox.m

@@ -0,0 +1,52 @@
+function res = cropOrientedBox(obj, obox, varargin)
+% Crop the content of an image within an oriented box.
+%
+%   RES = cropOrientedBox(IMG, OBOX)
+%   Crops the content of the image IMG that is contained within the
+%   oriented box OBOX. The size of the resulting image is approximately
+%   (due to rounding) the size of the oriented box.
+%
+%   Example
+%     % open and display input image
+%     img = Image.read('circles.png') ;
+%     figure; show(img); hold on;
+%     % identifies oriented box around the main region
+%     obox = regionOrientedBox(img > 0);
+%     drawOrientedBox(obox, 'g');
+%     % crop the content of the oriented box
+%     res = cropOrientedBox(img, obox);
+%     figure; show(res)
+%
+%   See also
+%     regionOrientedBox, crop
+%
+ 
+% ------
+% Author: David Legland
+% e-mail: david.legland@inrae.fr
+% INRAE - BIA Research Unit - BIBS Platform (Nantes)
+% Created: 2022-06-24,    using Matlab 9.12.0.1884302 (R2022a)
+% Copyright 2022 INRAE.
+
+% retrieve oriented box parameters
+boxCenter = obox(1:2);
+boxSize = obox(3:4);
+boxAngle = obox(5);
+
+% create the transform matrix that maps from box coords to global coords
+transfo = createTranslation(boxCenter) * createRotation(deg2rad(boxAngle));
+
+% sample points within the box (use single pixel spacing)
+lx = -floor(boxSize(1)/2):ceil(boxSize(1)/2);
+ly = -floor(boxSize(2)/2):ceil(boxSize(2)/2);
+
+% map into global coordinate space
+[y, x] = meshgrid(ly, lx);
+[x, y] = transformPoint(x, y, transfo);
+
+% evaluate within image, keeping type of original image
+resData = zeros(size(x), class(obj.Data));
+resData(:) = interp(obj, x, y);
+
+% create new image
+res = Image('data', resData, 'parent', obj);

src/@Image/interp.m

@@ -15,7 +15,7 @@
 
 % ------
 % Author: David Legland
-% e-mail: david.legland@inra.fr
+% e-mail: david.legland@inrae.fr
 % Created: 2011-12-14,    using Matlab 7.9.0.529 (R2009b)
 % Copyright 2011 INRA - Cepia Software Platform.
 
@@ -54,7 +54,7 @@
     y = yData(obj);
 
     if nc == 1
-        val = interp2(y, x, double(obj.Data), ...
+        val(:) = interp2(y, x, double(obj.Data), ...
             point(:, 2), point(:, 1), method, fillValue);
     else
         for i = 1:nc
@@ -69,7 +69,7 @@
     y = yData(obj);
     z = zData(obj);
     if nc == 1
-        val = interp3(y, x, z, double(obj.Data), ...
+        val(:) = interp3(y, x, z, double(obj.Data), ...
             point(:, 2), point(:, 1), point(:, 3), method, fillValue);
     else
         for i = 1:nc