How to smoothen the edges from an image obtained from imagesc function - matlab

Question

I have an RGB image obtained from saving the imagesc function as shown below. how to refine/smoothen the edges present in the image.
It consists of sharper edges, where I need to smoothen them. Im not able to find a solution for performing this for an RGB image. Instead of the staircase effect seen in the image I'd like to even out the edges. Please help thanks in advance.

Answer 1

maybe imresize will help you:
% here im just generating an image similar to yours
A = zeros(20);
for ii = -2:2
A = A + (ii + 3)*diag(ones(20-abs(ii),1),ii);
end
A([1:5 16:20],:) = 0;A(:,[1:5 16:20]) = 0;
subplot(121);
imagesc(A);
title('original')
% resizing image with bi-linear interpolation
B = imresize(A,100,'bilinear');
subplot(122);
imagesc(B);
title('resized')
EDIT
here I do resize + filtering + rounding:
% generates image
A = zeros(20);
for ii = -2:2
A = A + (ii + 3)*diag(ones(20-abs(ii),1),ii);
end
A([1:5 16:20],:) = 0;A(:,[1:5 16:20]) = 0;
subplot(121);
imagesc(A);
title('original')
% resizing
B = imresize(A,20,'nearest');
% filtering & rounding
C = ceil(imgaussfilt(B,8));
subplot(122);
imagesc(C);
title('resized')

Answer 2

solution
use imfilter and fspecial to perform a convolution of you image with gaussian.
I = imread('im.png');
H = fspecial('gaussian',5,5);
I2 = imfilter(I,H);
change 'blurlevel' parameter (which determines the gaussian kernel size) to make the image smoother or sharper.
result

Answer 3

If you are just looking for straighter edges, like an elevation map you can try contourf.
cmap = colormap();
[col,row] = meshgrid(1:size(img,2), 1:size(img,1));
v = linspace(min(img(:)),max(img(:)),size(cmap,1));
contourf(col,row,img,v,'edgecolor','none');
axis('ij');
This produces the following result using a test function that I generated.