Background remove from Image

remove the background from an image in MATLAB without using any built-in function.

This MATLAB code is used to remove the background from an image without using any built-in functions. The code performs the following steps:

1. Reads an image file and loads it into the variable img.
2. Converts the image to grayscale using the rgb2gray function. This is because the thresholding operation is performed on a grayscale image, as it represents the intensity values of each pixel.
3. Uses global thresholding to convert the grayscale image to a binary image. The graythresh function is used to determine the optimal threshold value for the image. The im2bw function is then used to convert the grayscale image to a binary image.
4. Invert the binary image
5. Multiply the binary image with the original image using repmat function to remove the background. This step sets the pixels corresponding to the background in the original image to 0.
6. Display the image using the imshow function.

This is a basic method to remove background, it may not work well with images that have complex backgrounds or have variations in intensity. You can use other methods like color-based or contour-based methods to improve the accuracy of removing background.