Upload billboard.py

billboard.py

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+import cv2
+import numpy as np
+
+# Create a named window for the display.
+win_name = 'Destination Image'
+
+# ------------------------------------------------------------------------------
+# Define mouse callback function.
+# ------------------------------------------------------------------------------
+def mouse_handler(event, x, y, flags, data):
+    if event == cv2.EVENT_LBUTTONDOWN:
+        # Render points as yellow circles in destination image.
+        cv2.circle(data['img'], (x, y), radius=5, color=(0, 255, 255), thickness=-1, lineType=cv2.LINE_AA)
+        cv2.imshow(win_name, data['img'])
+        if len(data['points']) < 4:
+            data['points'].append([x, y])
+
+# ------------------------------------------------------------------------------
+# Define convenience function for retrieving ROI points in destination image.
+# ------------------------------------------------------------------------------
+def get_roi_points(img):
+    # Set up data to send to mouse handler.
+    data = {'img': img.copy(), 'points': []}
+    # Set the callback function for any mouse event.
+    cv2.imshow(win_name, img)
+    cv2.setMouseCallback(win_name, mouse_handler, data)
+    cv2.waitKey(0)
+
+    # Convert the list of four separate 2D ROI coordinates to an array.
+    roi_points = np.vstack(data['points']).astype(float)
+
+    return roi_points
+
+# ------------------------------------------------------------------------------
+# Main function to apply homography and warp images.
+# ------------------------------------------------------------------------------
+def apply_homography_and_warp(img_src, img_dst, roi_dst):
+    # Compute the coordinates for the four corners of the source image.
+    size = img_src.shape
+    src_pts = np.array([[0, 0], [size[1] - 1, 0], [size[1] - 1, size[0] - 1], [0, size[0] - 1]], dtype=float)
+
+    # Compute the homography.
+    h, status = cv2.findHomography(src_pts, roi_dst)
+
+    # Warp source image onto the destination image.
+    warped_img = cv2.warpPerspective(img_src, h, (img_dst.shape[1], img_dst.shape[0]))
+
+    # Black out polygonal area in destination image.
+    cv2.fillConvexPoly(img_dst, roi_dst.astype(int), 0, 16)
+
+    # Add the warped image to the destination image.
+    img_dst = img_dst + warped_img
+
+    return img_dst
+
+# ------------------------------------------------------------------------------
+# Main program
+# ------------------------------------------------------------------------------
+
+# # Read the source image.
+# img_src = cv2.imread('Apollo-8-Launch.png')
+
+# # Read the destination image.
+# img_dst = cv2.imread('times_square.jpg')
+
+# # Get four corners of the billboard
+# print('Click on four corners of a billboard and then press ENTER')
+
+# # Retrieve the ROI points from the user mouse clicks.
+# roi_dst = get_roi_points(img_dst)
+
+# # Apply homography and warp the images.
+# result_img = apply_homography_and_warp(img_src, img_dst, roi_dst)
+
+# # Display the updated image with the virtual billboard.
+# cv2.imshow(win_name, result_img)
+
+# # Wait for a key to be pressed to exit.
+# cv2.waitKey(0)
+
+# # Close the window.
+# cv2.destroyAllWindows()