武汉理工大学数字图像处理英文课件 Chapter8（1）.pptVIP

Distortion Matlab Function distort (1/5) Matlab Function distort (2/5) Matlab Function distort (3/5) Matlab Function distort (4/5) Matlab Function distort (3/3) Distortion * original 20% barrel 20% pincushion im = imread(09.tif); d20p = distort(im,0.2); d20n = distort(im,-0.2); function out=distort(inp,distortion,base) %DISTORT distort image. % DISTORT distorts an image by the specified amount. % % OUT = DISTORT( INP , DISTORTION) returns an image which is the same % size as the input image INP, but which has been distorted by the % amount DISTORTION. If DISTORTION=0, the output image is the same % as the input. If DISTORTION0 then the center of the image is magnified % and the sides bow outward. For DISTORTION0, the center of the image % shrinks and the sides bow inward. % % OUT = DISTORT( INP, DISTORTION, BASE) zooms the final image by % the factor BASE. % % If no output is specified, the distorted image is displayed. % % For example, DISTORT( INP, 0.2) displays the image with 20% distortion. % % Class Support % ------------- % The input image can be of class uint8 or double. The output % image is of the same class as the input image. function out=distort(inp,distortion,base) error(nargchk(2,3,nargin)); % Check for 2 input arguments. [vlen,hlen,colors]=size(inp); % Size of input image. % Define output image as same type as input (double or uint8). output=zeros(vlen,hlen,colors); if isa(inp,uint8) output=im2uint8(output); end; xcen=hlen/2.0; % Horizontal center, in pixels. ycen=vlen/2.0; % Vertical center, in pixels. ds = 4.0/(hlen+vlen); % intermediate circle (inscribed in square) %ds = 2.0/min(hlen,vlen); % inscribed circle %ds = 2.0/sqrt(hlen^2+vlen^2); % circumscribed circle % Base magnification factor. if (nargin3) if (distortion0.0) rbase = min(hlen,vlen)*ds/2; else rbase = sqrt(hlen^2+vlen^2)*ds/2; end; base = 1.0/(1.0+distortion*rbase