Rotate Image

Rotate an image in X degrees.

Description

% rotate_image - rotates an image given inside a matrix by the amount of "degree" counter-clockwise
% using linear interpolation of the output grid points from the back-rotated input points
% in this way, the output image will never have a "blank" point
%
% Format: [out_image_m,out_ref_points_m] = rotate_image( degree, in_image_m, in_ref_points_m )
%
% Input: degree - rotation degree in dergees, counter-clockwise
% in_image_m - input image, given inside a matrix (gray level image only)
% in_ref_points_m - points on the image wich their output coordinates will be given
% after the rotation. given format of this matrix is:
% [ x1,x2,...,xn;y1,y2,...,yn]
%
% Output: out_image_m - the output image
% out_ref_points_m - the position of the input handle points after the rotation.
% this element is given in "in_ref_points_m" exists
% format of the matrix is the same as of "in_ref_points_m"
%
% NOTE: By definition of rotation, in order to perserve all the image inside the
% rotated image space, the output image will be a matrix with a bigger size.
%

Call the function with no parameters, to activate the demo

• Acknowledgements: This submission has inspired the following:; Automatic Image Registration
• MATLAB release: MATLAB 6.1 (R12.1)

[Meenal Bagla]

Could you possibly do this for a 3D matrix.

[amit mishra]

nice tool; the only problem is that the image expands after rotation, which shd not be the case;and the areas where there is no image in rest of the area; where as there shd be pixels all aroud using extrapolation!!

[K S]

Very Nice!

[Francisco Lopes]

Perfect. Congratulations.

[Alice Huang]

good

[PBO .]

Very useful and well documented: thanks !

[Sachin Gupta]

Excellent!! can u plz give the format of input test cases..

[Avinash .]

Extremely useful and well documented code!!!

[sulakshana borsune]

 

[Tim Peace]

 

[aa jam]

 

[Sudhir Gupta]

 

[Simon Robinson]

It's a bit of a strange feature that it gives an error for 90, 180, and 270 degree rotations if you don't specify a out_ref_points_m (if you aren't interested in this) but not for other angles, otherwise excellent.

[Shamem Ahmed]

Very interesting

[Ben hardy]

 

[David Moyles]

 

[Simone Scolding]

clever

[Steve Sharples]

Excellent code, thank you for sharing.

[Amanda Lin]

There is only 1 small suggestion. The images I have are in uint8. Your code at line 112 will give error message. So what I did was convert my image matrix to double and after rotation, convert the output matrix to uint8. So if you can check the input image's data first, do the conversion within your code when necessary, that'll be good.

[vaira prakash]

 

[Pearl]