Upload somefunc.py: contains the function aimed to perform demosaicing

src/methods/template/somefunc.py

+import numpy as np
+from scipy.signal import convolve2d
+
+from src.forward_model import CFA
+
+def bilinear_interpolation(op: CFA, z: np.ndarray) -> np.ndarray:
+    """Perform bilinear interpolation for demosaicing
+
+    Args:
+        op (CFA): CFA operator.
+        z (np.ndarray): Adjoint image.
+
+    Returns:
+        np.ndarray: Interpolated image.
+    """
+    # Bi-linear interpolation
+
+    ker_bayer_red_blue = np.array([[1, 2, 1], [2, 4, 2], [1, 2, 1]]) / 4
+    ker_bayer_green = np.array([[0, 1, 0], [1, 4, 1], [0, 1, 0]]) / 4
+
+    res = np.empty(op.input_shape)
+
+    res[:, :, 0] = convolve2d(z[:, :, 0], ker_bayer_red_blue, mode='same')
+    res[:, :, 1] = convolve2d(z[:, :, 1], ker_bayer_green, mode='same')
+    res[:, :, 2] = convolve2d(z[:, :, 2], ker_bayer_red_blue, mode='same')
+
+    return res
+
+def spectral_difference(op: CFA, z: np.ndarray, res: np.ndarray) -> np.ndarray:
+    """Perform spectral difference method for demosaicing
+
+    Args:
+        op (CFA): CFA operator.
+        z (np.ndarray): Adjoint image.
+        res (np.ndarray): Interpolated image.
+
+    Returns:
+        np.ndarray: Demosaicked image.
+    """
+
+    ker_bayer_red_blue = np.array([[1, 2, 1], [2, 4, 2], [1, 2, 1]]) / 4
+    ker_bayer_green = np.array([[0, 1, 0], [1, 4, 1], [0, 1, 0]]) / 4
+
+    # Computation of spectral differences
+
+    delta_red_green_quad =  z[:, :, 0] - np.multiply(res[:, :, 1],op.mask[:,:,0])
+    delta_red_blue_quad =  z[:, :, 0] - np.multiply(res[:, :, 2],op.mask[:,:,0])
+
+    delta_blue_green_quad =  z[:, :, 2] - np.multiply(res[:, :, 1],op.mask[:,:,2])
+    delta_blue_red_quad =  z[:, :, 2] - np.multiply(res[:, :, 0],op.mask[:,:,2])
+
+    delta_green_red_quad =  z[:, :, 1] - np.multiply(res[:, :, 0],op.mask[:,:,1])
+    delta_green_blue_quad =  z[:, :, 1] - np.multiply(res[:, :, 2],op.mask[:,:,1])
+
+    # Estimation
+    res_sd = np.empty(op.input_shape)
+
+    res_sd[:,:,0] = res[:, :, 1] + convolve2d(delta_red_green_quad,ker_bayer_red_blue,mode='same') + res[:, :, 2] + convolve2d(delta_red_blue_quad,ker_bayer_red_blue,mode='same') 
+    res_sd[:,:,2] = res[:, :, 1] + convolve2d(delta_blue_green_quad,ker_bayer_red_blue,mode='same') + res[:, :, 0] + convolve2d(delta_blue_red_quad,ker_bayer_red_blue,mode='same') 
+    res_sd[:,:,1] = res[:, :, 0] + convolve2d(delta_green_red_quad,ker_bayer_green,mode='same') + res[:, :, 2] + convolve2d(delta_green_blue_quad,ker_bayer_green,mode='same') 
+
+    return res_sd
+
+def normalization(res_sd:np.ndarray)-> np.ndarray:
+    """Perform a min-max normalization
+
+    Args:
+        res_sd (np.ndarray): Demosaicked image.
+
+    Returns:
+        np.ndarray: Normalized image.
+    """
+
+    res = (res_sd - np.min(res_sd)) / (np.max(res_sd) - np.min(res_sd))
+    
+    return res
+
+def quad_bayer_to_bayer_pattern(op: CFA):
+    """Quad to Bayer pattern conversion by swapping method
+
+    Args:
+        op (CFA): CFA operator.
+
+    Returns:
+        CFA: Bayer pettern.
+    """
+    if op.cfa == 'quad_bayer':
+        for j in range(1, op.mask.shape[1], 4):
+            op.mask[:,j], op.mask[:,j+1] = op.mask[:,j+1].copy(), op.mask[:,j].copy()
+
+        for i in range(1, op.mask.shape[0], 4):
+            op.mask[i, :], op.mask[i+1,:] = op.mask[i+1,:].copy(), op.mask[i,:].copy()
+            
+        for i in range(1, op.mask.shape[0], 4):
+            for j in range(1, op.mask.shape[1], 4):
+                op.mask[i,j], op.mask[i+1,j+1] = op.mask[i+1,j+1].copy(), op.mask[i,j].copy() 
+    return 0
+
+def quad_bayer_to_bayer_image(y:np.array):
+    """Quad to Bayer conversion of a mosaicked image by swapping method
+
+    Args:
+        y (np.array): Mosaicked image.
+    """
+        
+    for j in range(1, y.shape[1], 4):
+        y[:,j], y[:,j+1] = y[:,j+1].copy(), y[:,j].copy()
+
+    for i in range(1, y.shape[0], 4):
+        y[i, :], y[i+1,:] = y[i+1,:].copy(), y[i,:].copy()
+        
+    for i in range(1, y.shape[0], 4):
+        for j in range(1, y.shape[1], 4):
+            y[i,j], y[i+1,j+1] = y[i+1,j+1].copy(), y[i,j].copy() 
+            
+    return 0
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