为什么设置的曝光率和测试出的值不一样？

[yzrl]

曝光率和识别速度有关系吗？

# 红外RGB565跟踪示例

#

# 这个例子展示了使用OpenMV Cam进行红外RGB565跟踪。


import sensor, image
import time
#from numba import jit
from pyb import UART

import json
import utime

import pyb

#EXPOSURE_TIME_SCALE = 0.1
thresholds = (100,100,0,0,0,0) # thresholds for bright white light from IR.

TimeBin = [0,0]
TimeBox = [0,0]

sensor.reset()

sensor.set_pixformat(sensor.RGB565)

sensor.set_framesize(sensor.QQQVGA)

#sensor.set_windowing((60,80)) #将相机的分辨率设置为当前分辨率的子分辨率

sensor.set_auto_gain(False) # must be turned off for color tracking

sensor.set_auto_whitebal(False) # must be turned off for color tracking

sensor.skip_frames(time = 10)
sensor.get_exposure_us()#以毫秒为单位返回曝光率

sensor.set_auto_exposure(False,exposure_us=100)#设置曝光




#sensor.set_auto_exposure(False, \
   # exposure_us = int(current_exposure_time_in_microseconds* EXPOSURE_TIME_SCALE))


clock = time.clock() # Tracks FPS.

uart = UART(3,115200)



def find_max(blobs):
   max_size=0
   for blob in blobs:
        if blob.pixels() >max_size:
            max_blob=blob
#            max_size = blob.pixels()
   return max_blob



while(True):
    #utime.sleep_ms(50)
    #for i in range(0,6000):
    clock.tick()# Track elapsed milliseconds between snapshots().
    
   
    img = sensor.snapshot()#binary([thresholds], invert=True, zero=True)
    TimeBox[1]= TimeBox[0]
    TimeBox[0] = utime.ticks_ms()
    deal = utime.ticks_diff(TimeBox[0],TimeBox[1])
    print("deal :",deal)
   # start = utime.ticks_ms()
    blobs=img.find_blobs([thresholds],pixels_threshold=200,area_threshold=250)


    if blobs:

      output_str = json.dumps(blobs)

      max_blob=find_max(blobs)

      img.draw_rectangle(max_blob.rect(),color=(255,0,0))

      output_str="[%d,%d]" % (max_blob.cx(),max_blob.cy())

      #print('you send:',output_str)
      uart.write(output_str+'\n')

     # print("Initial exposure == %d" % sensor.set_auto_exposure())

      #current_exposure_time_in_microseconds=sensor.get_exposure_us()

      #sensor.set_auto_exposure(False, \
         # exposure_us = int(sensor.get_exposure_us() * EXPOSURE_TIME_SCALE))
      print("New exposure == %d" % sensor.get_exposure_us())
      
      TimeBin[1] = TimeBin[0]
      TimeBin[0] = utime.ticks_ms()
      delta= utime.ticks_diff(TimeBin[0], TimeBin[1])
      print('duration:',delta)

      print("FPS:", clock.fps())

            #img.draw_cross(blob.cx(), blob.cy())
    else:

                print('not found!')

[yzrl]

测试结果

[kidswong999]

每一个新的提问，单独发一个新帖子,我现在说“为什么设置的曝光率和测试出的值不一样？”

测试代码：

import sensor, image
import time
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QQQVGA)
#sensor.set_windowing((60,80)) #将相机的分辨率设置为当前分辨率的子分辨率
sensor.set_auto_gain(False) # must be turned off for color tracking
sensor.set_auto_whitebal(False) # must be turned off for color tracking
sensor.set_auto_exposure(False,exposure_us=196)#设置曝光
sensor.skip_frames(time = 1000)
while(True):
    print("New exposure == %d" % sensor.get_exposure_us())

结果：设置的196，获取到192。

原因：设置曝光值是按照档位设置的。会自动找到最接近的档位。