Why does my image does not conert to grayscale?

I need to convert an image that we were given to grayscale.

I wrote the code below. When I highlight the whole 'imagesc' line and 'evaluate selction' the image pops up but in color.

logo = imread('..._logo.jpg'); 
figure; 
imagesc(logo); 
colormap gray;

Answer 1

[Image Analyst]

Use imshow() because imagesc() applies some funky colormap by default, and that is usually not what you want.

[Andrew Killian]

So the full code like this? Do I even need that last line?

logo = imread('_logo.jpg'); 
I = rgb2gray(logo); 
figure; 
imshow(I); 
colormap gray; 

[Image Analyst]

No, you don't need that last line. The default for gray scale images is to not use a colormap and show everything in it's original, native gray color.

[Image Analyst]

Andrew, if this solved it, can you click the "Accept this answer" link? Thanks in advance.