Unrecognized function error.

Question

Andrew Killian 2021-8-31

回答： Gargi Patil 2021-9-3

I just want to count the number of non-white pixels in an image.

I have

pix = imread('/binary_image4.png');
nonZeroPixels = nnz(pix);

But when I evaluate selection of second line, I get " Unrecognized function or variable 'pix'."

per isakson 2021-8-31

编辑：per isakson 2021-8-31

Why the slash, "/"? Try

pix = imread('binary_image4.png');

You use LINUX, I guess.

Make sure imread() succeeds.

Answer 1

Gargi Patil 2021-9-3

Hi,

As mentioned in the comments, the forward slash in the path is not required. Ensure the image is on the MATLAB path or pass the required file path.

The code snippet shared works successfully for MATLAB's built-in demo binary image:

I = imread('circles.png');
nonZeroPixels  = nnz(I)
nonZeroPixels = 14134