Update keypoints.py script.
@@ -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)
@@ -32,14 +33,16 @@ 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)
+ 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])
