RGB to other image space

rgb_image = imread('peppers.png');
hsv_image = rgb2hsv(rgb_image);
ycbcr_image = rgb2ycbcr(rgb_image);
gray_image = rgb2gray(rgb_image);

cform = makecform('srgb2lab');
Lab_image = applycform(rgb_image,cform);

figure,imshow(Lab_image);

subplot(3,2,1),imshow(rgb_image)
subplot(3,2,2),imshow(hsv_image)
subplot(3,2,3),imshow(ycbcr_image)
subplot(3,2,4),imshow(Lab_image)
subplot(3,2,5),imshow(gray_image)