openmv/usr/examples/keypoints.py
iabdalkader c050509b9d Update descriptor scripts.
* Use the new match_descriptor.
* Add commented line that loads descriptor from file
2016-02-28 03:56:02 +02:00

54 lines
1.7 KiB
Python

import sensor, time, image
# Rotation.
NORMALIZED=False
# Keypoint extractor threshold, range from 0 to any number.
# This threshold is used when extracting keypoints, the lower
# the threshold the higher the number of keypoints extracted.
KEYPOINTS_THRESH=20
# Keypoint-level threshold, range from 0 to 100.
# This threshold is used when matching two keypoint descriptors, it's the
# percentage of the distance between two descriptors to the max distance.
# In other words, the minimum matching percentage between 2 keypoints.
MATCHING_THRESH=80
# Reset sensor
sensor.reset()
# Sensor settings
sensor.set_contrast(1)
sensor.set_gainceiling(16)
sensor.set_framesize(sensor.QQVGA)
sensor.set_pixformat(sensor.GRAYSCALE)
# Skip a few frames to allow the sensor settle down
# Note: This takes more time when exec from the IDE.
for i in range(0, 30):
img = sensor.snapshot()
img.draw_string(0, 0, "Please wait...")
kpts1 = None
# Uncomment to load keypoints from file
#kpts1 = image.load_descriptor(image.FREAK, "/desc.freak")
clock = time.clock()
while (True):
clock.tick()
img = sensor.snapshot()
kpts2 = img.find_keypoints(threshold=KEYPOINTS_THRESH, normalized=NORMALIZED)
if (kpts1==None):
kpts1 = kpts2
print(kpts1)
elif kpts2:
c = image.match_descriptor(image.FREAK, kpts1, kpts2, threshold=MATCHING_THRESH)
# C[3] contains the percentage of matching keypoints.
# If more than 25% of the keypoints match, draw stuff.
if (c[2]>25):
img.draw_cross(c[0], c[1], size=5)
img.draw_keypoints(kpts2, color=255, size=12)
img.draw_string(0, 10, "Match %d%%"%(c[2]))
# Draw FPS
img.draw_string(0, 0, "FPS:%.2f"%(clock.fps()))