To remove non-barcode regions in an image using MATLAB, you can use various image processing techniques such as thresholding, morphological operations, and edge detection. Here is a general approach you can follow:

1. Convert the image to grayscale using the rgb2gray function.
2. Apply thresholding to the grayscale image to segment the barcode from the background using the imbinarize function.
3. Perform morphological operations such as erosion, dilation, opening or closing, to remove any small regions or smooth out the image using the imerode, imdilate, imopen, or imclose functions.
4. Use edge detection algorithms such as the Canny edge detector or the Sobel operator to detect the edges of the barcode and remove any unwanted edges using the edge function.
5. Finally, apply a mask to the original image using the segmented barcode to remove the non-barcode regions.

Here is an example code snippet that demonstrates the above steps: 

% Read the image
img = imread('barcode_image.jpg');

% Convert the image to grayscale
gray_img = rgb2gray(img);

% Apply thresholding to segment the barcode
binary_img = imbinarize(gray_img);

% Perform morphological operations to remove small regions and smooth out the image
se = strel('square', 3);
binary_img = imopen(binary_img, se);

% Detect the edges of the barcode
edge_img = edge(binary_img, 'Canny');

% Remove unwanted edges
se = strel('line', 3, 90);
edge_img = imdilate(edge_img, se);

% Apply a mask to the original image to remove non-barcode regions
masked_img = bsxfun(@times, img, cast(edge_img, 'like', img));

Note that the exact parameters and steps required may vary depending on the specifics of your image and the barcode you are trying to detect. You may need to experiment with different techniques and parameters to find the best solution for your specific use case.

https://matlabhelpers.com/matlab-project-help.php