测距时的Lm是什么意思?
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这里用颜色来测距时,Lm是什么意思,实际长度?那例程中的length也是实际长度啊,Lm=色块长加宽除以2又是什么意思呀?
# Measure the distance # # This example shows off how to measure the distance through the size in imgage # This example in particular looks for yellow pingpong ball. import sensor, image, time # For color tracking to work really well you should ideally be in a very, very, # very, controlled enviroment where the lighting is constant... yellow_threshold = ( 56, 83, 5, 57, 63, 80) # You may need to tweak the above settings for tracking green things... # Select an area in the Framebuffer to copy the color settings. 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. clock = time.clock() # Tracks FPS. K=5000#the value should be measured while(True): clock.tick() # Track elapsed milliseconds between snapshots(). img = sensor.snapshot() # Take a picture and return the image. blobs = img.find_blobs([yellow_threshold]) if len(blobs) == 1: # Draw a rect around the blob. b = blobs[0] img.draw_rectangle(b[0:4]) # rect img.draw_cross(b[5], b[6]) # cx, cy Lm = (b[2]+b[3])/2 length = K/Lm print(length) #print(clock.fps()) # Note: Your OpenMV Cam runs about half as fast while # connected to your computer. The FPS should increase once disconnected.