Some simple templatematching with ORB

templatematching_ORB.py

import sys
import cv2
import numpy as np
from math import sqrt, acos
from optparse import OptionParser

#FULL = "full.jpg"
#CROP = "crop.jpg"
#FULL = "pleiades_hyades_50percent.jpg"
#CROP = "pleiades_hyades_50percent_crop.jpg"
#FULL = "baum0vbhs9m8xf.jpg"
#CROP = "baum0vbhs9m8xf_crop.jpg"


MATCH_COUNT = 10

if __name__ == '__main__':
    
    parser = OptionParser()
    (options, args) = parser.parse_args()
    
    if len(args) != 2:
        print "Usage: templatematching image1 crop"
        sys.exit(0)

    
    full = cv2.imread(args[0])          # queryImage
    crop = cv2.imread(args[1]) # trainImage
    img2 = cv2.cvtColor(full, cv2.COLOR_BGR2GRAY)
    img1 = cv2.cvtColor(crop, cv2.COLOR_BGR2GRAY)
    
    # Initiate SIFT detector
    orb = cv2.ORB_create()
    print orb
    
    # find the keypoints and descriptors with SIFT
    kp1, des1 = orb.detectAndCompute(img1, None)
    kp2, des2 = orb.detectAndCompute(img2, None)
    
    # create BFMatcher object
    bf = cv2.BFMatcher(cv2.NORM_HAMMING, crossCheck=True)
    
    # Match descriptors.
    matches = bf.match(des1,des2)

    
    # Sort them in the order of their distance.
    matches = sorted(matches, key = lambda x:x.distance)[:MATCH_COUNT]
    for m in matches:
        print m.distance
    
    if len(matches) >= MATCH_COUNT:
        src_pts = np.float32([ kp1[m.queryIdx].pt for m in matches ]).reshape(-1,1,2)
        dst_pts = np.float32([ kp2[m.trainIdx].pt for m in matches ]).reshape(-1,1,2)
    
        M, mask = cv2.findHomography(src_pts, dst_pts, cv2.RANSAC, 5.0)
        matchesMask = mask.ravel().tolist()
    
        h,w = img1.shape
        pts = np.float32([ [0,0],[0,h-1],[w-1,h-1],[w-1,0] ]).reshape(-1,1,2)
        dst = cv2.perspectiveTransform(pts,M)
        mp = cv2.perspectiveTransform(np.float32([[w/2.0, h/2.0]]).reshape(-1,1,2), M)[0][0]
        cv2.circle(img2, (mp[0], mp[1]), 5, 255, -1)
    
        #img2 = cv2.polylines(img2,[np.int32(dst)],True,255,3, cv2.LINE_AA)
    else:
        print "Not enough matches! (minimum is %d matches" % MATCH_COUNT
        sys.exit()
    
    # Draw matches.
    img2 = cv2.polylines(img2, [np.int32(dst)], True, 255, 5, cv2.LINE_AA)
    img3 = cv2.drawMatches(img1, kp1, img2, kp2, matches, None, flags=2)
    result = cv2.polylines(full, [np.int32(dst)], True, (255, 255, 255), 5, cv2.LINE_AA)
    cv2.circle(result, (mp[0], mp[1]), 2, (255, 255, 255), -1)
    cv2.circle(result, (mp[0], mp[1]), 10, (255, 255, 255), 2)
    
    ###########
    # calculate info
    ###########
    # vector of upper edge
    vec = dst[3][0] - dst[0][0]
    #print sqrt(np.dot(vec, vec))
    # zoom factor crop width / full width
    zoom = img2.shape[1] / sqrt(np.dot(vec, vec))
    # angle upper edge to x axis
    angle = acos(np.dot(vec, np.array([1, 0])) / (sqrt(vec[0]**2 + vec[1]**2)))    
    
    print args[0], args[1]
    print "middlepoint:", mp
    print "zoom:", zoom
    print "angle:", np.rad2deg(angle)
    print "corners:"
    print "\n".join([str(i[0]) for i in dst])
    
    ### write data to file
    with open("results.txt", "a") as f:
        f.write("\n")
        f.write("%s %s\n" % (args[0], args[1]))
        f.write("middlepoint: %s\n" % str(mp) )
        f.write("zoom: %.2f\n" % zoom )
        f.write("angle: %.2f\n" % np.rad2deg(angle) )
        f.write("corners: %s\n" % ", ".join([str(i[0]) for i in dst]))

    
    cv2.namedWindow("image", cv2.WINDOW_NORMAL)
    cv2.imshow('image', img3)
    cv2.waitKey(0)
    cv2.imshow('image', result)
    cv2.waitKey(0)