diff --git a/usr/examples/09-Feature-Detection/keypoints.py b/usr/examples/09-Feature-Detection/keypoints.py index a6cffd5d2..aea10bd02 100644 --- a/usr/examples/09-Feature-Detection/keypoints.py +++ b/usr/examples/09-Feature-Detection/keypoints.py @@ -10,7 +10,8 @@ sensor.reset() # Sensor settings sensor.set_contrast(1) sensor.set_gainceiling(16) -sensor.set_framesize(sensor.QCIF) +sensor.set_framesize(sensor.VGA) +sensor.set_windowing((240, 240)) sensor.set_pixformat(sensor.GRAYSCALE) sensor.set_auto_gain(False, value=100) @@ -32,22 +33,24 @@ clock = time.clock() while (True): clock.tick() img = sensor.snapshot() - # NOTE: See the docs for other arguments - kpts2 = img.find_keypoints(max_keypoints=100, scale_factor=1.2) - - if (kpts2 and kpts1 == None): - kpts1 = kpts2 + if (kpts1 == None): + # NOTE: By default find_keypoints returns multi-scale keypoints extracted from an image pyramid. + kpts1 = img.find_keypoints(max_keypoints=150, threshold=20, scale_factor=1.1) draw_keypoints(img, kpts1) - elif kpts2: - c = image.match_descriptor(kpts1, kpts2, threshold=85) - match = c[6] # C[6] contains the number of matches. - if (match>5): - img.draw_rectangle(c[2:6]) - img.draw_cross(c[0], c[1], size=10) + else: + # NOTE: When extracting keypoints to match the first descriptor, we use normalized=True to extract + # keypoints from the first scale only, which will match one of the scales in the first descriptor. + kpts2 = img.find_keypoints(max_keypoints=150, threshold=20, normalized=True) + if (kpts2): + c = image.match_descriptor(kpts1, kpts2, threshold=80) + match = c[6] # C[6] contains the number of matches. + if (match>5): + img.draw_rectangle(c[2:6]) + img.draw_cross(c[0], c[1], size=10) - print(kpts2, "matched:%d dt:%d"%(match, c[7])) - # NOTE: uncomment if you want to draw the keypoints - #img.draw_keypoints(kpts2, size=KEYPOINTS_SIZE, matched=True) + print(kpts2, "matched:%d dt:%d"%(match, c[7])) + # NOTE: uncomment if you want to draw the keypoints + #img.draw_keypoints(kpts2, size=KEYPOINTS_SIZE, matched=True) # Draw FPS img.draw_string(0, 0, "FPS:%.2f"%(clock.fps()))