Single Color Code Tracking Example

# This work is licensed under the MIT license.
# Copyright (c) 2013-2023 OpenMV LLC. All rights reserved.
# https://github.com/openmv/openmv/blob/master/LICENSE
#
# Single Color Code Tracking Example
#
# This example shows off single color code tracking using the OpenMV Cam.
#
# A color code is a blob composed of two or more colors. The example below will
# only track colored objects which have both the colors below in them.

import csi
import time
import math

# Color Tracking Thresholds (L Min, L Max, A Min, A Max, B Min, B Max)
# The below thresholds track in general red/green things. You may wish to tune them...
thresholds = [
    # generic_red_thresholds -> index is 0 so code == (1 << 0)
    (30, 100, 15, 127, 15, 127,),
    # generic_green_thresholds -> index is 1 so code == (1 << 1)
    (30, 100, -64, -8, -32, 32),
]
# Codes are or'ed together when "merge=True" for "find_blobs".

csi0 = csi.CSI()
csi0.reset()
csi0.pixformat(csi.RGB565)
csi0.framesize(csi.QVGA)
csi0.snapshot(time=2000)
csi0.auto_gain(False)  # must be turned off for color tracking
csi0.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" must be set to merge overlapping color blobs for color codes.

while True:
    clock.tick()
    img = csi0.snapshot()
    for blob in img.find_blobs(
        thresholds, pixels_threshold=100, area_threshold=100, merge=True
    ):
        if blob.code == 3:  # r/g code == (1 << 1) | (1 << 0)
            # 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(image.get_major_axis_line(blob), color=(0, 255, 0))
                img.draw_line(image.get_minor_axis_line(blob), color=(0, 0, 255))
            # These values are stable all the time.
            img.draw_detection(blob)
            # Note - the blob rotation is unique to 0-180 only.
            img.draw_keypoints(
                [(blob.cx, blob.cy, int(math.degrees(blob.rotation)))], size=20
            )
    print(clock.fps())