Refactor depth2disparity function for improved stability and clarity

scripts/Depth2Disparity/depth2disparity.py

@@ -24,7 +24,7 @@ def relative2abs(rel_depth_map, coord1, dist1, coord2, dist2):
     return abs_depth_map
 
 def depth2disparity(abs_depth_map, baseline=0.176, disp_scale=2.0, disp_offset=-120):
-  
+    
     # Get image dimensions
     height, width = abs_depth_map.shape
 
@@ -45,25 +45,32 @@ def depth2disparity(abs_depth_map, baseline=0.176, disp_scale=2.0, disp_offset=-
             # Retrieve the absolute depth (r_t) for this pixel
             r_t = abs_depth_map[i, j]
 
-            # Avoid division by zero for invalid or infinite depth values
+            # Avoid invalid or infinite depth values
             if r_t <= 0:
                 disparity_map[i, j] = 0
                 continue
 
-            # Calculate angular disparity (d) using the spherical depth-to-disparity formula
             try:
-                angle_disp = np.arctan(
-                    baseline / (r_t * np.sin(theta_t) + r_t * np.cos(theta_t) * np.tan(theta_t))
-                ) - theta_t
+                # Compute denominator with stability checks
+                epsilon = 1e-8  # Small value to prevent division instability
+                tan_theta_t = np.tan(theta_t) if np.abs(np.cos(theta_t)) > epsilon else np.sign(np.sin(theta_t)) * np.inf
+
+                denominator = r_t * np.sin(theta_t) + r_t * np.cos(theta_t) * tan_theta_t
+                if denominator <= 0:
+                    disparity_map[i, j] = 0
+                    continue
+
+                # Calculate angular disparity (d)
+                angle_disp = np.arctan(baseline / denominator) - theta_t
 
                 # Convert angular disparity to pixel disparity
                 disparity_map[i, j] = (angle_disp / (unit_h * np.pi) - disp_offset) * disp_scale
+
             except ZeroDivisionError:
                 disparity_map[i, j] = 0
 
     return disparity_map
 
-
 if __name__ == "__main__":
     # Set up argument parser
     parser = argparse.ArgumentParser(description="Convert relative depth map to absolute depth map.")