Simultaneous recognition of color and template matching

Video tutorial 18 - Combination of algorithms: https://singtown.com/learn/50029/

This section shares how to perform color recognition and template matching simultaneously. Take the recognition of red and green digital templates as an example. First, we perform color recognition, and then perform template recognition in the recognized color area.

Our recognition image is as follows：

Before running the program, save our template image to the SD card.

# 多颜色多模板匹配示例
#
# 这个例子显示了使用OpenMV的多色跟踪。

import sensor, image, time
from image import SEARCH_EX, SEARCH_DS

# 颜色跟踪阈值(L Min, L Max, A Min, A Max, B Min, B Max)
# 下面的阈值跟踪一般红色/绿色的东西。你不妨调整他们...
thresholds = [(30, 100, 15, 127, 15, 127), # generic_red_thresholds
              (30, 100, -64, -8, -32, 32), # generic_green_thresholds
              (0, 15, 0, 40, -80, -20)] # generic_blue_thresholds
# 不要超过16个颜色阈值
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QQVGA)
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()

# 只有比“pixel_threshold”多的像素和多于“area_threshold”的区域才被
# 下面的“find_blobs”返回。 如果更改相机分辨率，
# 请更改“pixels_threshold”和“area_threshold”。 “merge = True”合并图像中所有重叠的色块。

templates = ["/0.pgm", "/1.pgm", "/2.pgm", "/6.pgm"] #保存多个模板

while(True):
    clock.tick()
    img = sensor.snapshot()
    for blob in img.find_blobs(thresholds, pixels_threshold=200, area_threshold=200):
        #img.draw_rectangle(blob.rect())
        #img.draw_cross(blob.cx(), blob.cy())
        #print(blob.code())

        img = img.to_grayscale()
        for t in templates:
            template = image.Image(t)
            #对每个模板遍历进行模板匹配
            r = img.find_template(template, 0.70, step=4, search=SEARCH_EX) #, roi=(10, 0, 60, 60))
        #find_template(template, threshold, [roi, step, search]),threshold中
        #的0.7是相似度阈值,roi是进行匹配的区域（左上顶点为（10，0），长80宽60的矩形），
        #注意roi的大小要比模板图片大，比frambuffer小。
        #把匹配到的图像标记出来
            if r:
                img.draw_rectangle(r, color=0)
                print(blob.code(), t) #打印模板名字
                #如果为红色, blob.code()==1; 如果为绿色, blob.code==2.
                #如果为数字0, t=="0.pgm"; 如果为数字1, t=="1.pgm".


    #print(clock.fps())

The effect of running the program is as follows:

The output of the running result in the terminal: