how to convert rgb image to 11*92 grayscale image of type 'pgm' ?

wen I try to conert an image using photo editor, the converted image size will b 112 92 3.. i.e. dimension wil b 3,, how can make it 1D?

Answer 1

[David Sanchez]

First use

gray_image = rgb2gray(RGB_image);

The rescale the image:

B = imresize(gray_image, scale)

Take a look at

doc rgb2gray
doc imresize

The order of the operations can be reverse.

Answer 2

[Image Analyst]

% Convert to grayscale.
grayImage = rgb2gray(rgbImage);
% Resize to 11*92 or 112*92 (whatever is wanted), if necessary.
grayImage = imresize(grayImage, [112, 92]);
% Convert to pgm format disk file
imwrite(grayImage, 'myFile.pgm');