为什么识别到人脸的时候没有显示框？测量温度偏低怎么解决？

[3sq1]

import sensor, image, time, fir, lcd

from pid import PID
from pyb import Servo

pan_servo=Servo(1)
tilt_servo=Servo(2)

pan_servo.calibration(500,2500,500)
tilt_servo.calibration(500,2500,500)

red_threshold  = (13, 49, 18, 61, 6, 47)

pan_pid = PID(p=0.07, i=0, imax=90) #脱机运行或者禁用图像传输，使用这个PID
tilt_pid = PID(p=0.05, i=0, imax=90) #脱机运行或者禁用图像传输，使用这个PID
#pan_pid = PID(p=0.1, i=0, imax=90)#在线调试使用这个PID
#tilt_pid = PID(p=0.1, i=0, imax=90)#在线调试使用这个PID

ALT_OVERLAY = False # 设置为True分配第二个ir图像
sensor.reset() # Initialize the camera sensor.
sensor.set_pixformat(sensor.RGB565) # use RGB565.
sensor.set_framesize(sensor.QQVGA2) # use QQVGA for speed.

sensor.skip_frames(time = 2000) # Let new settings take affect.
sensor.set_auto_whitebal(False) # turn this off.

fir.init(type=fir.FIR_AMG8833)

# 初始化lcd
lcd.init()

# 为更流畅的视频分配另一个帧缓冲。
extra_fb = sensor.alloc_extra_fb(sensor.width(), sensor.height(), sensor.RGB565)

clock = time.clock() # Tracks FPS.
face_cascade = image.HaarCascade("frontalface", stages=25)

def find_max(blobs):
    max_size=0
    for blob in blobs:
        if blob[2]*blob[3] > max_size:
            max_blob=blob
            max_size = blob[2]*blob[3]
    return max_blob


while(True):
    clock.tick() # Track elapsed milliseconds between snapshots().
    img = sensor.snapshot() # Take a picture and return the image.

    faces = img.find_features(face_cascade, threshold=0.5, scale=1.25)
    if faces:
        face = find_max(faces)
        cx = int(face[0]+face[2]/2)
        cy = int(face[1]+face[3]/2)
        pan_error = cx-img.width()/2
        tilt_error = cy-img.height()/2

        print("pan_error: ", pan_error)

        img.draw_rectangle(face) # rect
        img.draw_cross(cx, cy) # cx, cy

        pan_output=pan_pid.get_pid(pan_error,1)
        tilt_output=tilt_pid.get_pid(tilt_error,1)
        print("pan_output",pan_output)
        pan_servo.angle(int(pan_servo.angle()+pan_output))
        tilt_servo.angle(int(tilt_servo.angle()+tilt_output))
        
    ta, ir, to_min, to_max = fir.read_ir()

    if not ALT_OVERLAY:
        # 缩放图像并使用framebuffer进行绑定
        fir.draw_ir(img, ir)
    else:
        # 创建一个副图像，然后混合到帧缓冲区中。
        extra_fb.clear()
        fir.draw_ir(extra_fb, ir, alpha=256)
        img.blend(extra_fb, alpha=128)

    # 绘制环境温度、最小温度和最大温度。
    img.draw_string(8, 0, "Ta: %0.2f C" % ta, color = (255, 0, 0), mono_space = False)
    img.draw_string(8, 8, "To min: %0.2f C" % to_min, color = (255, 0, 0), mono_space = False)
    img.draw_string(8, 16, "To max: %0.2f C"% to_max, color = (255, 0, 0), mono_space = False)

    lcd.display(img)
    # Force high quality streaming...
    # 强制高质量流…
    img.compress(quality=90)

    # 打印FPS
    print(clock.fps())!

[kidswong999]

你的画面就没有人脸啊。你把红外热图覆盖上了，人脸肯定看不到。