How to Create a Spot the Difference Program Using Image Processing in MATLAB

Spot the difference is a fun and engaging puzzle where you need to spot the differences between two images. This article will guide you through creating such a program using image processing techniques in MATLAB.

Getting Started

Before diving into the code, ensure that you have MATLAB installed on your system. This tutorial assumes basic knowledge of MATLAB programming.

Step 1: Load the Images

The first step is to load two images into MATLAB. These images should be the same size and ideally have the same background to ensure accurate comparison.

Code Snippet

image1 imread('');
image2 imread('');

Step 2: Convert Images to Grayscale

To simplify the comparison, convert the images to grayscale. Grayscale images make it easier to identify the differences by focusing on luminance.

Code Snippet

gray1 rgb2gray(image1);
gray2 rgb2gray(image2);

Step 3: Compute the Difference

Subtract one grayscale image from the other to find the differences. The result will be a new image where the differences are highlighted.

Code Snippet

diffImage imabsdiff(gray1, gray2);

Step 4: Threshold the Difference

Apply a threshold to create a binary image where the differences are highlighted. This step helps in isolating the differences by converting the grayscale image into a binary image.

Code Snippet

thresholdValue 30; Adjust this value as needed
binaryDiff imbinarize(diffImage, thresholdValue / 255);

Step 5: Clean Up the Binary Image

Use morphological operations to clean up the binary image and remove noise. This helps in improving the clarity of the differences identified.

Code Snippet

cleanedDiff bwareaopen(binaryDiff, 50); Remove small objects
cleanedDiff imfill(cleanedDiff, 'holes'); Fill holes

Step 6: Display the Results

Finally, display the original images alongside the differences. This will help in visualizing the differences clearly.

Code Snippet

figure；
subplot(1, 3, 1);
imshow(image1);
title('Image 1');
subplot(1, 3, 2);
imshow(image2);
title('Image 2');
subplot(1, 3, 3);
imshow(cleanedDiff);
title('Differences');

Complete Code

Heres the complete code for reference:

image1 imread('');
image2 imread('');
gray1 rgb2gray(image1);
gray2 rgb2gray(image2);
diffImage imabsdiff(gray1, gray2);
thresholdValue 30; Adjust this value as needed
binaryDiff imbinarize(diffImage, thresholdValue / 255);
cleanedDiff bwareaopen(binaryDiff, 50); Remove small objects
cleanedDiff imfill(cleanedDiff, 'holes'); Fill holes
figure;
subplot(1, 3, 1);
imshow(image1);
title('Image 1');
subplot(1, 3, 2);
imshow(image2);
title('Image 2');
subplot(1, 3, 3);
imshow(cleanedDiff);
title('Differences');

Additional Considerations

Image Alignment

Ensure that the images are perfectly aligned. If they are not, consider using feature matching techniques to align them before processing.

Adjusting Parameters

You may need to adjust the threshold and area parameters depending on the specific images you are using to get optimal results.

GUI Development

For a more user-friendly application, consider developing a GUI using MATLABs App Designer or GUIDE. This will allow users to easily load and compare images without needing to write code from scratch.

The basic program described here should help you get started with spotting differences in images using MATLAB! If you have specific requirements or need further enhancements, feel free to ask!