色块寻找?求没找到色块发送个0?
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# Single Color RGB565 Blob Tracking Example # # This example shows off single color RGB565 tracking using the OpenMV Cam. import sensor, image, time, math threshold_index = 0 # 0 for red, 1 for green, 2 for blue # Color Tracking Thresholds (L Min, L Max, A Min, A Max, B Min, B Max) # The below thresholds track in general red/green/blue things. You may wish to tune them... thresholds = [(30, 100, 30, 127, -40, 60), # generic_red_thresholds (15, 40, -10, 40, -50, 20), # generic_block_thresholds (60, 80, 0, 64, -10,40)] # generic_blue_thresholds sensor.reset() sensor.set_pixformat(sensor.RGB565) sensor.set_framesize(sensor.QVGA) sensor.skip_frames(time = 1000) sensor.set_auto_gain(False) # must be turned off for color tracking sensor.set_auto_whitebal(False) # must be turned off for color tracking clock = time.clock() # Only blobs that with more pixels than "pixel_threshold" and more area than "area_threshold" are # returned by "find_blobs" below. Change "pixels_threshold" and "area_threshold" if you change the # camera resolution. "merge=True" merges all overlapping blobs in the image. while(True): clock.tick() img = sensor.snapshot() for blob in img.find_blobs([thresholds[threshold_index]], pixels_threshold=400, area_threshold=500, merge=True): # These values depend on the blob not being circular - otherwise they will be shaky. if blob.elongation() > 0.5: img.draw_edges(blob.min_corners(), color=(255,0,0)) img.draw_line(blob.major_axis_line(), color=(0,255,0)) img.draw_line(blob.minor_axis_line(), color=(0,0,255)) # These values are stable all the time. img.draw_rectangle(blob.rect()) img.draw_cross(blob.cx(), blob.cy()) # Note - the blob rotation is unique to 0-180 only. img.draw_keypoints([(blob.cx(), blob.cy(), int(math.degrees(blob.rotation())))], size=20) try: print(threshold_index,blob[4]) except NameError: print(1) threshold_index=threshold_index+1 if threshold_index>1: threshold_index=0
我是多色块寻找,返回色块颜色和大小,但是blob【4】这个变量无法更改,更改就报错,我试过del blob也没用,
try函数是第一次没找到报错用的!
最后效果想的是如果没找到色块,返回个0就好
求大佬帮助啊
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blobs = img.find_blobs() if blobs: for blob in blobs: xxxx else: print(0)