Merge branch 'master' of https://github.com/taddeus/licenseplates

src/GetPlate.py

-from pylab import array, zeros, inv, dot, svd, shape
-from Interpolation import pV
-
-def getPlateAt(image, points, M, N):
-    '''Returns an image of size MxN of the licenseplate (or any rectangular 
-    object) defined by 4 corner points.'''
-    # Construct the matrix M
-    x1_a, y1_a = 0, 0
-    x2_a, y2_a = M, 0
-    x3_a, y3_a = M, N
-    x4_a, y4_a = 0, N
-    
-    p_i = []
-    
-    for point in points:
-        p_i.append([point.x, point.y])
-    
-    mat_M = array([[p_i[0][0], p_i[0][1], 1, 0,  0,  0, \
-                        -x1_a * p_i[0][0], -x1_a * p_i[0][1], -x1_a], \
-                   [0,  0,  0, p_i[0][0], p_i[0][1], 1, \
-                        -y1_a * p_i[0][0], -y1_a * p_i[0][1], -y1_a], \
-                   [p_i[1][0], p_i[1][1], 1, 0,  0,  0, \
-                        -x2_a * p_i[1][0], -x2_a * p_i[1][1], -x2_a], \
-                   [0,  0,  0, p_i[1][0], p_i[1][1], 1, \
-                        -y2_a * p_i[1][0], -y2_a * p_i[1][1], -y2_a], \
-                   [p_i[2][0], p_i[2][1], 1, 0,  0,  0, \
-                        -x3_a * p_i[2][0], -x3_a * p_i[2][1], -x3_a], \
-                   [0,  0,  0, p_i[2][0], p_i[2][1], 1, \
-                        -y3_a * p_i[2][0], -y3_a * p_i[2][1], -y3_a], \
-                   [p_i[3][0], p_i[3][1], 1, 0,  0,  0, \
-                        -x4_a * p_i[3][0], -x4_a * p_i[3][1], -x4_a], \
-                   [0,  0,  0, p_i[3][0], p_i[3][1], 1, \
-                        -y4_a * p_i[3][0], -y4_a * p_i[3][1], -y4_a]])
-    
-    # Get the vector p and the values that are in there by taking the SVD. 
-    # Since D is diagonal with the eigenvalues sorted from large to small on
-    # the diagonal, the optimal q in min ||Dq|| is q = [[0]..[1]]. Therefore, 
-    # p = Vq means p is the last column in V.
-    U, D, V = svd(mat_M)
-    p = V[8][:]                
-    a, b, c, d, e, f, g, h, i = p[0], \
-                                p[1], \
-                                p[2], \
-                                p[3], \
-                                p[4], \
-                                p[5], \
-                                p[6], \
-                                p[7], \
-                                p[8]
-    
-    # P is the resulting matrix that describes the transformation
-    P = array([[a, b, c], \
-               [d, e, f], \
-               [g, h, i]])
-    
-    # Create the new image
-    b = array([zeros(M, float)] * N)
-    for i in range(0, M):
-        for j in range(0, N):
-            or_coor = dot(inv(P),([[i],[j],[1]]))
-            or_coor_h = or_coor[1][0] / or_coor[2][0], \
-                      or_coor[0][0] / or_coor[2][0]
-            b[j][i] = pV(image, or_coor_h[0], or_coor_h[1])
-    
-    return b

src/GetPlateTest.py

-from GetPlate import getPlateAt
-from GrayscaleImage import GrayscaleImage
-from Point import Point
-
-# Define the corners of the licenseplate
-points = [Point(None, (310, 383)), \
-          Point(None, (382, 381)), \
-          Point(None, (382, 396)), \
-          Point(None, (310, 398))]
-
-# Get the image
-image = GrayscaleImage('../images/test_plate.png')
-
-# Let the code get the licenseplate
-output_image = getPlateAt(image, points, 100, 20)
-
-# Show the licenseplate                 
-output_image = GrayscaleImage(None, output_image)
-output_image.show()