1 / 12

Computer Vision in Matlab lab#3

Computer Vision in Matlab lab#3. By Engr. Muhammad Saqib. Histogram of color image. %% Matlab script for the histogram of color image clc ; % Clear the command window. close all; % Close all figures (except those of imtool .) imtool close all; % Close all imtool figures.

kendra
Download Presentation

Computer Vision in Matlab lab#3

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Computer Vision in Matlablab#3 By Engr. Muhammad Saqib

  2. Histogram of color image %% Matlab script for the histogram of color image clc; % Clear the command window. close all; % Close all figures (except those of imtool.) imtool close all; % Close all imtool figures. clear; % Erase all existing variables. workspace; % Make sure the workspace panel is showing. fontSize = 20; % Read in standard MATLAB color demo image. rgbImage = imread('peppers.png'); [rows columns numberOfColorBands] = size(rgbImage); subplot(2, 2, 1); imshow(rgbImage, []); title('Original Color Image', 'Fontsize', fontSize);

  3. Histogram of color image contd.. redPlane = rgbImage(:, :, 1); greenPlane = rgbImage(:, :, 2); bluePlane = rgbImage(:, :, 3); % Let's get its histograms. [pixelCountRgrayLevelsR] = imhist(redPlane); subplot(2, 2, 2); plot(pixelCountR, 'r'); title('Histogram of red plane', 'Fontsize', fontSize); [pixelCountGgrayLevelsG] = imhist(greenPlane); subplot(2, 2, 3); plot(pixelCountG, 'g'); title('Histogram of green plane', 'Fontsize', fontSize); [pixelCountBgrayLevelsB] = imhist(bluePlane); subplot(2, 2, 4); plot(pixelCountB, 'b'); title('Histogram of blue plane', 'Fontsize', fontSize);

  4. Binary images using thresholding  % Matlab script for binary image I=imread('trees.tif'); % Read in 1st image T=im2bw(I, 0.1); % perform thresholding subplot(1,3,1), imshow(I); % Display original image subplot(1,3,2), imshow(T); % Display thresholded image

  5. Thresholding contd.. A=imread('toycars1.png'); % Read in 1st image B=imread('toycars2.png'); % Read in 2nd image Abw=im2bw(A); % convert to binary Bbw=im2bw(B); % convert to binary subplot(1,3,1), imshow(Abw); % Display 1st image subplot(1,3,2), imshow(Bbw); % Display 2nd image Output = xor(Abw, Bbw); % xor images images subplot(1,3,3), imshow(Output); % Display result

  6. Thresholding contd.. I=imread('coins.png'); % read in image level = graythresh(I); % get OTSU theshold It = im2bw(I, level); % theshold image imshow(It); % display it

  7. Adaptive thresholding in matlab %% Adaptive thresholding clear;close all; im1=imread('page.png'); im2=imread('tshape.png'); bwim1=adaptivethreshold(im1,11,0.03,0); bwim2=adaptivethreshold(im2,15,0.02,0); subplot(2,2,1); imshow(im1); subplot(2,2,2); imshow(bwim1); subplot(2,2,3); imshow(im2); subplot(2,2,4); imshow(bwim2);

  8. Function for adaptive threshold function bw=adaptivethreshold(IM,ws,C,tm) if (nargin<3) error('You must provide the image IM, the window size ws, and C.'); elseif (nargin==3) tm=0; elseif (tm~=0 && tm~=1) error('tm must be 0 or 1.'); end IM=mat2gray(IM); if tm==0 mIM=imfilter(IM,fspecial('average',ws),'replicate'); else mIM=medfilt2(IM,[wsws]); end sIM=mIM-IM-C; bw=im2bw(sIM,0); bw=imcomplement(bw);

  9. Image Morphology • Dilation t=imread('text.tif'); % Original Image sq=ones(3,3); % structuring element td=imdilate(t,sq); subplot(1,2,1),imshow(t) subplot(1,2,2),imshow(td)

  10. Image Morphology contd.. • Erosion c=imread('circbw.tif'); %read original image sq=ones(3,3); %structuring element ce=imerode(c,sq); subplot(1,2,1),imshow(c) subplot(1,2,2),imshow(ce)

  11. An application: boundary detection • Assignment #1 Question#1 Write a matlab code for the following

  12. Opening and Closing • Assignment #2 • Question#2 Implement this code in matlab and discuss the results in detail cr=[0 1 0;1 1 1;0 1 0]; sq=ones(3,3); test=zeros(10,10);test(2:6,2:4)=1;test(3:5,6:9)=1;test(8:9,4:8)=1;test(4,5)=1 imopen(test,sq) imopen(test,cr) imclose(test,sq) imclose(test,cr)

More Related