OpenMV学习笔记2——颜色识别

目录

一、打开单颜色识别实例代码

二、代码基础部分

 三、阈值选择

四、给识别到的颜色画框

五、多颜色识别 

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一、打开单颜色识别实例代码

如图，双击打开对应文件即可进入实例代码。

二、代码基础部分

# Single Color RGB565 Blob Tracking Example
#
# This example shows off single color RGB565 tracking using the OpenMV Cam.

import sensor
import time
import 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, 15, 127, 15, 127),  # generic_red_thresholds
    (30, 100, -64, -8, -32, 32),  # generic_green_thresholds
    (0, 30, 0, 64, -128, 0),      # generic_blue_thresholds
]  

sensor.reset()
sensor.set_pixformat(sensor.RGB565)
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()

# 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=200,
        area_threshold=200,
        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.mi