例程讲解10-Color-Tracking->automatic_grayscale_color_tracking自动灰度颜色追踪

视频教程4 - 颜色识别：https://singtown.com/learn/49993/

# 自动灰度颜色追踪例程
#
# 这个例子展示了使用OpenMV的单色自动灰度色彩跟踪。

import sensor, image, time
print("Letting auto algorithms run. Don't put anything in front of the camera!")

sensor.reset()
sensor.set_pixformat(sensor.GRAYSCALE)
sensor.set_framesize(sensor.QVGA)
sensor.skip_frames(time = 2000)
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()

# 捕捉图像中心的颜色阈值。
r = [(320//2)-(50//2), (240//2)-(50//2), 50, 50] # 50x50 center of QVGA.

print("Auto algorithms done. Hold the object you want to track in front of the camera in the box.")
print("MAKE SURE THE COLOR OF THE OBJECT YOU WANT TO TRACK IS FULLY ENCLOSED BY THE BOX!")
for i in range(60):
    img = sensor.snapshot()
    img.draw_rectangle(r)

print("Learning thresholds...")
threshold = [128, 128] # Middle grayscale values.
for i in range(60):
    img = sensor.snapshot()
    hist = img.get_histogram(roi=r)
    lo = hist.get_percentile(0.01) # 获取1％范围的直方图的CDF（根据需要调整）！
    hi = hist.get_percentile(0.99) # 获取1％范围的直方图的CDF（根据需要调整）！
    # 平均百分位值。
    threshold[0] = (threshold[0] + lo.value()) // 2
    threshold[1] = (threshold[1] + hi.value()) // 2
    for blob in img.find_blobs([threshold], pixels_threshold=100, area_threshold=100, merge=True, margin=10):
        img.draw_rectangle(blob.rect())
        img.draw_cross(blob.cx(), blob.cy())
        img.draw_rectangle(r)

print("Thresholds learned...")
print("Tracking colors...")

while(True):
    clock.tick()
    img = sensor.snapshot()
    for blob in img.find_blobs([threshold], pixels_threshold=100, area_threshold=100, merge=True, margin=10):
        img.draw_rectangle(blob.rect())
        img.draw_cross(blob.cx(), blob.cy())
    print(clock.fps())

星瞳科技OpenMV官方中文文档函数讲解：

星瞳科技OpenMV官方中文文档函数讲解：