Perfectly fitting an image on a pushbutton of my GUI

I have created a GUI where I have two pushbuttons, I have embedded an image on these pushbuttons, but as you can see there are the button images, but they have black spaces around, because the original image has them. My question is if there is an effective way of deleting those black spaces that are around of the real part of the image I want (play button and save button), so only the button part of the image appears.

I have used this code to fit the image to the pushbuttons

%Play button
[a,map]=imread('play_button.png');
[r,c,d]=size(a); 
x=ceil(r/45); 
y=ceil(c/60); 
g=a(1:x:end,1:y:end,:);
g(g==255)=5.5*255;
set(handles.play_button,'CData',g);

I have attached an image of the GUI with those 2 buttons. And I have also attached the original images of the play button and save button.

Answer 1

[hamdah alotaibi]

instead of ceil() method, use floor()

good luck :)