ROTATE_CVIP

rotate_cvip() - Rotate an image by a given angle (in degrees).

Contents

SYNTAX

[outImage] = rotate_cvip(inImage, theta)

Input Parameters include:

Output Parameter includes:

DESCRIPTION

The function rotates the image by the degree specified by the user. The transformation equations used are X=xcos(rads)+ysin(rads); Y=-xsin(rads)+ycos(rads); Where, X=shifted x co-ordinate, Y = shifted y co-ordinate, and rads = number of radians to be rotated. For the 4 corners of the image, the shifted co-ordinates are found out and from that the new image size can be calculated. For each co-ordinate in the new image the corresponding co-ordinate in the old image is calculated, if it falls with in the range of the old image size,the corresponding pixel value is copied, otherwise the pixel value is set to zero.

REFERENCE

1. Scott E Umbaugh. DIGITAL IMAGE PROCESSING AND ANALYSIS: Applications with MATLAB and CVIPtools, 3rd Edition.

EXAMPLE

% Read image

 I = imread('cam.bmp');

% Calling function using default parameters

 O1 = rotate_cvip(I);

% Theta

 theta = -60;

% Calling function using user defined parameters

 O2 = rotate_cvip(I,-60);

% Display input image

 figure; imshow(I); title('Input image');

% Display output image

 figure; imshow(O1/255);title('Output image using default parameters');

 figure; imshow(O2/255);title('Output image using user defined parameters');

CREDITS

Author: Norsang Lama, Febrauary 2017
Copyright © 2017-2018 Scott E Umbaugh
For updates visit CVIP Toolbox Website

Published with MATLAB® R2014b