如何在MATLAB中将索引图像转换为RGB图像？

Question

I did a gaussian filter and the image become index. I have to use imagesc to show the determine the color difference. How can I convert it to rgb so that I can do further process.

Edited Added some images, top is the 'original image', 'imshow(C)', 'imagesc(C)' respectively. Then I just want the 'C' variable to be like imagesc image. Is it possible??

Edited Here is my coding, see from gaussian onward

% Read Image
rgb = imread('barcode.jpg');
% Resize Image
rgb = imresize(rgb,0.33);
%figure(),imshow(rgb);
% Convert from RGB to Gray
Igray = rgb2gray(rgb);
BW2 = edge(Igray,'canny');
%figure(),imshow(BW2);
% Perform the Hough transform
[H, theta, rho] = hough(BW2);
 % Find the peak pt in the Hough transform
peak = houghpeaks(H);
 % Find the angle of the bars
barAngle = theta(peak(2));
J = imrotate(rgb,barAngle,'bilinear','crop');
%figure(),imshow(J);
Jgray = double(rgb2gray(J));
% Calculate the Gradients
[dIx, dIy] = gradient(Jgray);
%if min(dIx(:))<= -100 && max(dIx(:))>=100 || min(dIy(:))<=-100 && max(dIy(:))>=100
if barAngle <= 65 && barAngle >=-65 && min(dIx(:))<= -100
    B =  abs(dIx) - abs(dIy);
else
    B = abs(dIy) - abs(dIx);
end
% Low-Pass Filtering
H = fspecial('gaussian', 20, 10);
C = imfilter(B, H);
C = imclearborder(C);
figure(),imshow(C);
figure(),imagesc(C);colorbar;

Answer 1

RGB = ind2rgb(X,map)

RGB is just eye-candy at this point, you can't magically add information that isn't there.

EDIT

In your code, C is a gray-scale image, because B is gray-scale which in terms is caused by the fact that it is composed from gradients dIx and dIy that originate from an image, you yourself make grayscale explicitly with the line Jgray = double(rgb2gray(J));