Why is my image appearing all white? I am trying to detect its edges with the following code..

clc;
clf;
i=imread('AB_1-16_pH_7.jpg');
subplot(421);
imshow(i);
title('orginalimage');
j=rgb2gray(i);
subplot(422);
imshow(j);
title('grayimage');
subplot(423);
m=edge(j,'canny');
imshow(11);
title('edge with canny function');
subplot(424);
figure(2)
m=imread('AB_1-16_pH_7.jpg');
imshow(m);
title('base image');

[Star Strider]

Posting or attaching your image would help.

Answer 1

[Image Analyst]

Because you don't show the edge image. You're displaying 11 (eleven).

Here, try this improved code:

% Boilerplate initialization stuff
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 20;

% Read in original RGB image.
filename = 'peppers.png'
rgbImage = imread(filename);
subplot(2,2,1);
imshow(rgbImage);
title('Original Image', 'FontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);

% Convert to grayscale.
grayImage=rgb2gray(rgbImage);
subplot(2,2,2);
imshow(grayImage);
title('Gray Scale Image', 'FontSize', fontSize);

% Get edge image.
edgeImage = edge(grayImage, 'canny');
subplot(2,2,3);
imshow(edgeImage, []);
title('Edge Image with Canny function', 'FontSize', fontSize);

Answer 2

[Neo]

Thank you for answering my question. I am a beginning coder, I was wondering what resources would you recommend so that I can read up on how to advance my coding because some of the coding that you used is foreign to me, such as format long g; format compact; and % Enlarge figure to full screen. set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]); Where can I learn? I have read a few chapters from a digital processing textbook but it is not sufficient to enable me to write the code I want. Thanks, Neo.

[Image Analyst]

For individual commands, look them up in the help. In general, to learn MATLAB, see this link: http://www.mathworks.com/matlabcentral/answers/8026-best-way-s-to-master-matlab.

It looks like my code does a Canny edge and it's not all white so it looks like I solved your problem, so if you wouldn't mind officially "Accepting" my answer, I'd appreciate it.