How to get vision.TemplateMatcher to work with colored templates and images?

I've been working with the computer vision toolbox, and trying out to use vision.TemplateMatcher to use a template of a truecolor image to find if the template exists on another truecolor image. The documentation says it is however I am getting

Error using vision.TemplateMatcher/parenReference

Data with more than two dimensions is not supported for this System object.

My code looks like this:

Jf=imread("JettFront.png");
picture=imread("Screenshot (186).png");
tMatcher= vision.TemplateMatcher;
location=tMatcher(picture, Jf);

Any ideas on what I should do?

[Satwik]

Hi,

I understand the documention for 'vision.TemplateMatcher' suggests that we can use both truecolor and M-by-N 2-D grayscale image as input arguments. However, 'imread' results in a M-by-N-by-3 array when used on a truecolor image. This might be the probable cause for the error :

"Data with more than two dimensions is not supported for this System object.".

As a workaround, I suggest converting the truecolor image into grayscale using the 'rgb2gray' function before using it with 'vision.TemplateMatcher'.

For more information on the usage of 'rgb2gray', you may refer to the following documentation:

https://www.mathworks.com/help/matlab/ref/rgb2gray.html

Answer 1

[Hitesh]

Hi Tim,

The error you are encountering is due to the "vision.TemplateMatcher" system object does not support truecolor (RGB) images directly. It expects grayscale images, which are two-dimensional. To resolve this, you need to convert your truecolor images to grayscale before using the vision.TemplateMatcher.

Kindly refer to the revised code and comments mentioned:

Jf = imread("JettFront.png");
picture = imread("Screenshot (186).png");

% Convert the images to grayscale
JfGray = rgb2gray(Jf);
pictureGray = rgb2gray(picture);

% Create the template matcher object
tMatcher = vision.TemplateMatcher;

% Find the location of the template in the image
location = tMatcher(pictureGray, JfGray);

For more information regarding the "vision.TemplateMatcher", kindly refer to the following MATALB Documentation:

https://www.mathworks.com/help/vision/ref/vision.templatematcher-system-object.html