Legend for Classified image

I have classified LISS 3 imagery using maximum likelihood method. I want to include legend for this classified output. Totally i classified 5 groups. how can i add legend for this output?

I have tried get(gca,'children') option but the legend was empty.

Kindly help me in this regard.

Warm regards Shoba

[Sukuchha]

if you have mapping toolbox then you can use lcolorbar function.

example from help: figure; colormap(jet(5)) labels = {'apples','oranges','grapes','peachs','melons'}; lcolorbar(labels,'fontweight','bold');

[Massimo Zanetti]

This is the best answer, didn't know about the labeled colorbar.

Many thanks.

Answer 1

[Image Analyst]

Use text() to write out a text string in the color of the class in the image. For example, if class 1 is shown in red, then

text(column, row, 'Class 1 is red', 'Color', [1, 0, 0], 'FontSize', 24);

Of course you need to specify what row and column you want to place the upper left (or is it upper right) of your text string. Do similar code for the other classes/colors.

[Shoba]

text() will provide the text for the particular class at the given location in the resultant imagery. But i need legend for all the classes in a separate box. I have assigned different color for 5 classes as per the below code

   img_class=zeros(siz(1),siz(2),3);
    for i=1:siz(1)
        for j=1:siz(2)
            A=[img1(i,j)-c1_mean(1);img2(i,j)-c1_mean(2);img3(i,j)-c1_mean(3);img4(i,j)-c1_mean(4)];
            p1=d_c1+(A'*s1*A);
            B=[img1(i,j)-c2_mean(1);img2(i,j)-c2_mean(2);img3(i,j)-c2_mean(3);img4(i,j)-c2_mean(4)];
            p2=d_c2+(B'*s2*B);
            C=[img1(i,j)-c3_mean(1);img2(i,j)-c3_mean(2);img3(i,j)-c3_mean(3);img4(i,j)-c3_mean(4)];
            p3=d_c3+(C'*s3*C);
            D=[img1(i,j)-c4_mean(1);img2(i,j)-c4_mean(2);img3(i,j)-c4_mean(3);img4(i,j)-c4_mean(4)];
            p4=d_c4+(D'*s4*D);
            E=[img1(i,j)-c5_mean(1);img2(i,j)-c5_mean(2);img3(i,j)-c5_mean(3);img4(i,j)-c5_mean(4)];
            p5=d_c5+(E'*s5*E);
            p=min([p1 p2 p3 p4 p5]);
            if p==p1
                img_class(j,i,1)=255;
                img_class(j,i,2)=0;
                img_class(j,i,3)=0;

            end
            if p==p2
                img_class(j,i,1)=0;
                img_class(j,i,2)=255;
                img_class(j,i,3)=0;

            end
            if p==p3
                img_class(j,i,1)=0;
                img_class(j,i,2)=0;
                img_class(j,i,3)=255;

            end
            if p==p4
                img_class(j,i,1)=185;
                img_class(j,i,2)=100;
                img_class(j,i,3)=50;

            end
            if p==p5
                img_class(j,i,1)=65;
                img_class(j,i,2)=93;
                img_class(j,i,3)=89;

            end
        end
    end

What should i do to have a legend box with colors and class names in the resultant classified image. Kindly help me.....

Warm Regards Shoba

[Image Analyst]

An axes can't take a legend when it's displaying an image. You'll have to write your own little function to draw a box with text and lines inside it with the desired colors. Use text() and line().

[Shoba]

thank you so much...

[Image Analyst]

Please mark as Accepted if we're done. Thanks.