Merge remote-tracking branch 'origin/master'

Author: Yash Srivastava

1.py

@@ -0,0 +1,164 @@
+import matplotlib.pyplot as plt
+import numpy as np
+import PIL
+from PIL import Image
+
+def get_input_lines(im, min_lines=3):
+
+ n = 0
+ lines = np.zeros((3, 0))
+ centers = np.zeros((3, 0))
+
+ plt.figure()
+ plt.imshow(im)
+ print('Set at least %d lines to compute vanishing point' % min_lines)
+ while True:
+ print('Click the two endpoints, use the right key to undo, and use the middle key to stop input')
+ clicked = plt.ginput(2, timeout=0, show_clicks=True)
+ if not clicked or len(clicked) < 2:
+ if n < min_lines:
+ print('Need at least %d lines, you have %d now' % (min_lines, n))
+ continue
+ else:
+ # Stop getting lines if number of lines is enough
+ break
+
+ # Unpack user inputs and save as homogeneous coordinates
+ pt1 = np.array([clicked[0][0], clicked[0][1], 1])
+ pt2 = np.array([clicked[1][0], clicked[1][1], 1])
+ # Get line equation using cross product
+ # Line equation: line[0] * x + line[1] * y + line[2] = 0
+ line = np.cross(pt1, pt2)
+ lines = np.append(lines, line.reshape((3, 1)), axis=1)
+ # Get center coordinate of the line segment
+ center = (pt1 + pt2) / 2
+ centers = np.append(centers, center.reshape((3, 1)), axis=1)
+
+ # Plot line segment
+ plt.plot([pt1[0], pt2[0]], [pt1[1], pt2[1]], color='b')
+
+ n += 1
+
+ return n, lines, centers
+
+def plot_lines_and_vp(im, lines, vp):
+
+ bx1 = min(1, vp[0] / vp[2]) - 10
+ bx2 = max(im.shape[1], vp[0] / vp[2]) + 10
+ by1 = min(1, vp[1] / vp[2]) - 10
+ by2 = max(im.shape[0], vp[1] / vp[2]) + 10
+
+ plt.figure()
+ plt.imshow(im)
+ for i in range(lines.shape[1]):
+ if lines[0, i] < lines[1, i]:
+ pt1 = np.cross(np.array([1, 0, -bx1]), lines[:, i])
+ pt2 = np.cross(np.array([1, 0, -bx2]), lines[:, i])
+ else:
+ pt1 = np.cross(np.array([0, 1, -by1]), lines[:, i])
+ pt2 = np.cross(np.array([0, 1, -by2]), lines[:, i])
+ pt1 = pt1 / pt1[2]
+ pt2 = pt2 / pt2[2]
+ plt.plot([pt1[0], pt2[0]], [pt1[1], pt2[1]], 'g')
+
+ plt.plot(vp[0] / vp[2], vp[1] / vp[2], 'ro')
+ plt.show()
+
+def get_top_and_bottom_coordinates(im, obj):
+
+ plt.figure()
+ plt.imshow(im)
+
+ print('Click on the top coordinate of %s' % obj)
+ clicked = plt.ginput(1, timeout=0, show_clicks=True)
+ x1, y1 = clicked[0]
+ # Uncomment this line to enable a vertical line to help align the two coordinates
+ # plt.plot([x1, x1], [0, im.shape[0]], 'b')
+ print('Click on the bottom coordinate of %s' % obj)
+ clicked = plt.ginput(1, timeout=0, show_clicks=True)
+ x2, y2 = clicked[0]
+
+ plt.plot([x1, x2], [y1, y2], 'b')
+
+ return np.array([[x1, x2], [y1, y2], [1, 1]])
+
+def get_vanishing_point(lines):
+
+ vp = np.zeros((3, 1))
+ #vp[0] = (lines[0])/(-1*lines[2])
+ #vp[1] = (lines[1])/(-1*lines[3])
+ #vp[0:1] = (lines[0:1,:])/(-1*lines[2,:])
+ b = []
+ print(lines)
+ for i in range (0,2):
+ b.append(lines[i])
+ c = lines[2]
+ #print(lines.shape())
+
+ b = np.array(b)
+ c = np.array(c)
+ #b = b.reshape(1,-1)
+ c = c.reshape(1,-1)
+ print ("c",c)
+ print ("b",b)
+ 
+ b = b.T
+ c = c.T
+ print ("c_new",c)
+ print ("b_new",b)
+ #print("b and c",b.T," ", c)
+ d = np.matmul(b.T,c)
+ print ("d",d)
+ 
+ a = np.matmul(np.linalg.inv(np.matmul(np.transpose(b),b)), np.matmul(b.T,c))
+ # print (c)
+ # print (b)
+ print ("a",a)
+ vp[2] = 1
+ pass
+
+def get_horizon_line(vpts):
+
+ print("Hello!")
+ print("vpts",vpts)
+ horizon = real(np.matmul(np.transpose(vpts[2]), np.transpose(vpts[0])))
+ length = sqrt(horizon[0]^2 + horizon[1]^2)
+ horizon = horizon/length
+ print(horizon)
+ pass
+
+def plot_horizon_line(im,vpts):
+
+plt.figure()
+ plt.imshow(im)
+
+ plt.plot([pt1[0], pt2[0]], [pt1[1], pt2[1]], color='b')
+ plt.show()
+ 
+ pass
+
+im = np.asarray(Image.open('CSL.jpg'))
+
+# Part 1
+# Get vanishing points for each of the directions
+num_vpts = 3
+vpts = np.zeros((3, num_vpts))
+
+for i in range(num_vpts):
+
+ print('Getting vanishing point %d' % i)
+ # Get at least three lines from user input
+ n, lines, centers = get_input_lines(im)
+ # <YOUR IMPLEMENTATION> Solve for vanishing point
+ vpts[:, i] = get_vanishing_point(lines)
+ # Plot the lines and the vanishing point
+ plot_lines_and_vp(im, lines, vpts[:, i])
+
+# <YOUR IMPLEMENTATION> Get the ground horizon line
+horizon_line = get_horizon_line(vpts)
+# <YOUR IMPLEMENTATION> Plot the ground horizon line
+plot_horizon_line(im,vpts)
+
+# Part 2
+# <YOUR IMPLEMENTATION> Solve for the camera parameters (f, u, v)
+f, u, v = get_camera_parameters()