MATLAB Video: how to use 'readFrame' output for 'imbinarize' function?

Question

I'm doing the following:1. Loading the original video 2. converting the video to black and white 3. saving it to a new avi file. Repeating for each frame.

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However I got the the following error:

Expected I to be two-dimensional

Why am I getting this error message? Isn't a frame going to be two-dimensional?

Answer 1

The image from your video is an RGB image so it is M x N x 3 and imbinarize only accepts 2D inputs. In order to process your image, you'll want to first convert it from RGB to grayscale using rgb2gray

img = rgb2gray(readFrame(reader));

Also, since the output of imbinarize is logical , you'll need to first convert it to a double prior to writing it to the output video

writeVideo(writer, double(BW));