Add new color random grid scheme

Author: coduri

docs/assets/readme/web_dec1.png

@@ -0,0 +1,106 @@
+import numpy as np
+from PIL import Image
+from scripts.random_grid.rg_grayscale_additive_SS import create_random_grid, create_difference_grid
+
+
+# Returns a dictionary containing function mappings and metadata for the algorithm (used by the web interface).
+def get_config():
+    return {
+        "name": "RG - Color (RGB) Additive Secret Sharing",
+        "description": get_description(),
+        "requirements": get_requirements(),
+        "encrypt": encrypt,
+        "decrypt": decrypt,
+        "extension": "png",
+        "image_type": "RGB"
+    }
+
+
+# Defines the expected inputs for encryption/decryption (number of images and additional parameters)
+def get_requirements():
+    return {
+        "encryption": {
+            "num_images": 1,
+            "parameters": {}  # No extra parameters needed
+        },
+        "decryption": {
+            "num_images": 2,
+            "parameters": {}  # No extra parameters needed
+        }
+    }
+
+
+# Returns a dictionary containing the description and reference links for the algorithm.
+def get_description():
+    return {
+        "text": "This (2,2) Visual Secret Sharing Scheme extends the general additive secret sharing scheme to handle RGB color images.",
+        "links": [
+            {"text": "Kafri & Keren",
+             "url": "https://doi.org/10.1364/ol.12.000377"}
+        ]
+    }
+
+
+# Function to encrypt an image by generating two shares using random grids and difference grids
+def encrypt(image):
+    """
+    Encrypts an image by generating two shares using random grids and difference grids.
+
+    Parameters:
+    image (PIL.Image.Image): The input image (PIL Image object) to be encrypted.
+
+    Returns:
+    tuple: A tuple containing two PIL.Image.Image objects (grid1_image and grid2_image),
+           representing the encrypted shares of the original image.
+    """
+    img_array = np.array(image).astype(int)  # Convert PIL Image to numpy array and convert to int type
+
+    # Create the first random grid for each channel and stack them
+    grid1 = np.stack([create_random_grid(img_array.shape[:2]) for _ in range(3)], axis=-1)
+    grid1_image = Image.fromarray(grid1)
+
+    # Create the second grid using modular subtraction
+    grid2 = create_difference_grid(img_array, grid1)
+    grid2_image = Image.fromarray(grid2.astype(np.uint8))
+
+    return grid1_image, grid2_image
+
+
+# Function to decrypt two images by overlaying the grids
+def decrypt(image1, image2):
+    """
+    Combines two grids by adding the second grid to the first.
+
+    Parameters:
+    image1 (PIL.Image.Image): The first image (PIL Image object), to be converted to numpy array and processed.
+    image2 (PIL.Image.Image): The second image (PIL Image object), to be converted to numpy array and processed.
+
+    Returns:
+    PIL.Image.Image: The resulting image (PIL Image object) after adding the two grids.
+    """
+    img1_array = np.array(image1.convert('RGB'))  # Convert PIL Image to numpy array (RGB)
+    img2_array = np.array(image2.convert('RGB'))  # Convert PIL Image to numpy array (RGB)
+
+    # Combine the grids using modular addition
+    decrypted = img1_array + img2_array
+    return Image.fromarray(decrypted.astype(np.uint8))  # Convert numpy array back to PIL Image
+
+
+if __name__ == '__main__':
+    image_path = '../images/test.png'
+    output_path = '../images/output/'
+
+    # Load and convert the input image to RGB
+    image = Image.open(image_path).convert('RGB')
+
+    # ENCRYPT: Generate shares
+    share1, share2 = encrypt(image)
+    share1.save(output_path + "RG1.png")
+    share2.save(output_path + "RG2.png")
+
+    # DECRYPT: Overlay the grids
+    img_share1 = Image.open(output_path + "RG1.png")  # PIL Image (RGB)
+    img_share2 = Image.open(output_path + "RG2.png")  # PIL Image (RGB)
+
+    out = decrypt(img_share1, img_share2)
+    out.save(output_path + "decrypted_image.png")

docs/assets/readme/web_dec2.png

@@ -58,7 +58,7 @@ def create_random_grid(size):
 # Function to create a difference grid by subtracting the image from the random grid
 def create_difference_grid(image, grid):
     """
-    Creates a difference grid by subtracting the pixel values of the input image from the random grid.
+    Creates a difference grid by subtracting the pixel values of the random grid image from the input image.
 
     Parameters:
     image (numpy.ndarray): The binary image array (as a numpy array) to subtract from the grid.
@@ -73,7 +73,7 @@ def create_difference_grid(image, grid):
 # Function to overlay two grids by performing subtraction
 def decrypt(image1, image2):
     """
-    Combines two grids by subtracting the second grid from the first.
+    Combines two grids by adding the second grid to the first.
 
     Parameters:
     image1 (PIL.Image.Image): The first image (PIL Image object), to be converted to numpy array and processed.

docs/assets/readme/web_enc1.png

@@ -1,12 +1,13 @@
 from scripts.visual_cryptography import vc_grayscale_halftone, vc_color_cmyk
-from scripts.random_grid import rg_grayscale_halftone, rg_grayscale_bitplane, rg_grayscale_additive_SS
+from scripts.random_grid import rg_grayscale_halftone, rg_grayscale_bitplane, rg_grayscale_additive_SS, rg_color_additive_SS
 
 # Using get_config() to retrieve the dictionaries with function mappings
 ALGORITHM_MODULES = {
-    "vc_grayscale_halftone": vc_grayscale_halftone.get_config(),
-    "vc_color_cmyk": vc_color_cmyk.get_config(),
-
+    "rg_color_additive_SS": rg_color_additive_SS.get_config(),
     "rg_grayscale_additive_SS": rg_grayscale_additive_SS.get_config(),
     "rg_grayscale_halftone": rg_grayscale_halftone.get_config(),
     "rg_grayscale_bitplane": rg_grayscale_bitplane.get_config(),
+
+    "vc_grayscale_halftone": vc_grayscale_halftone.get_config(),
+    "vc_color_cmyk": vc_color_cmyk.get_config(),
 }