颜色特征识别—识别红色，黄色，绿色，蓝色排针的数量

import sensor, image, time

green_threshold   = ( 0, 80, -70, -10, -0, 30)

red_threshold = ( 15, 50, 40, 80, 20, 60)

blue_threshold = ( 30, 50, 0, 20, -45, -20)

yellow_threshold = ( 65, 80, -10, 10, 60, 70)

green_number = 0

red_number = 0

blue_number = 0

yellow_number = 0

sensor.reset() # Initialize the camera sensor.

sensor.set_pixformat(sensor.RGB565) # use RGB565.

sensor.set_framesize(sensor.QQVGA) # use QQVGA for speed.

sensor.skip_frames(10) # Let new settings take affect.

sensor.set_auto_whitebal(False) # turn this off.

#关闭白平衡。白平衡是默认开启的，在颜色识别中，需要关闭白平衡。

clock = time.clock() # Tracks FPS.

while(True):

clock.tick() # Track elapsed milliseconds between snapshots().

img = sensor.snapshot() # Take a picture and return the image.

green_blobs = img.find_blobs([green_threshold])

if green_blobs:

for b in green_blobs:

img.draw_rectangle(b[0:4],color=(255,255,255))

green_number = green_number + 1

red_blobs = img.find_blobs([red_threshold])

if red_blobs:

for b in red_blobs:

img.draw_rectangle(b[0:4],color=(255,255,255))

red_number = red_number + 1

blue_blobs = img.find_blobs([blue_threshold])

if blue_blobs:

for b in blue_blobs:

img.draw_rectangle(b[0:4],color=(255,255,255))

blue_number = blue_number + 1

yellow_blobs= img.find_blobs([yellow_threshold])

if yellow_blobs:

for b in yellow_blobs:

img.draw_rectangle(b[0:4],color=(255,255,255))

yellow_number = yellow_number + 1

print( green_number, red_number, blue_number, yellow_number)

green_number = 0

red_number = 0

blue_number = 0

yellow_number = 0