Question

首先将视频帧分为三个不同的帧。然后，我将该图像转换为灰度图像。转换后，我需要找到哪一帧比其他两帧的黑色最多。我不知道如何查找图像中存在多少黑色。

我在互联网上已经经历过一些方法，但是我不知道如何实现它们？

import cv2
import sys
sys.path.append('/usr/local/lib/python2.7/site-packages')

import cv2
import numpy as np
import time
import copy

cap = cv2.VideoCapture(0)

while True:
    ret, frame = cap.read()
    output = frame.copy()
    gray = cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)
    cv2.imshow('gray',gray)
    cv2.imshow('frame',frame)
    gray = cv2.cvtColor(output, cv2.COLOR_BGR2GRAY)
    gray =255-gray
    ret, thresh = cv2.threshold(gray, 225, 255, cv2.THRESH_BINARY_INV)
    output, contours, hierarchy = cv2.findContours(thresh, cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
    output = cv2.drawContours(output, contours, -1,(0,0,255),3)
    cv2.imshow('frame',output)
    height, width = output.shape[:2]
    print (output.shape)

    start_row, start_col = int(0), int(0)
    # Let's get the ending pixel coordinates (bottom right of cropped top)
    end_row, end_col = int(height), int(width*.3)
    cropped_top = output[start_row:end_row , start_col:end_col]
    print (start_row, end_row) 
    print (start_col, end_col)

    cv2.imshow("Cropped Topp", cropped_top) 



    # Let's get the starting pixel coordiantes (top left of cropped bottom)
    start_row, start_col = int(0), int(width*.3)
    # Let's get the ending pixel coordinates (bottom right of cropped bottom)
    end_row, end_col = int(height), int(width)
    cropped_bot = output[start_row:end_row , start_col:end_col]
    print (start_row, end_row )
    print (start_col, end_col)

    ##cv2.imshow("Cropped Bot", cropped_bot) 
    ##cv2.waitKey(0) 
    ##cv2.destroyAllWindows()

    start_row, start_col = int(0), int(0)
    # Let's get the ending pixel coordinates (bottom right of cropped top)
    end_row, end_col = int(height), int(width*.3)
    cropped_top = cropped_bot[start_row:end_row , start_col:end_col]
    print (start_row, end_row) 
    print (start_col, end_col)

    cv2.imshow("Cropped Top", cropped_top) 



    # Let's get the starting pixel coordiantes (top left of cropped bottom)
    start_row, start_col = int(0), int(width*.3)
    # Let's get the ending pixel coordinates (bottom right of cropped bottom)
    end_row, end_col = int(height), int(width)
    cropped_mid = cropped_bot[start_row:end_row , start_col:end_col]
    print (start_row, end_row )
    print (start_col, end_col)

    cv2.imshow("Cropped Bot", cropped_mid) 
##    #cv2.imwrite('plsal1.png',h)
    if cv2.waitKey(1) & 0xff == ord('q'):
            break

cap.release()
cv2.destroyAllWindows()

我需要知道如何检测图像中的黑色并将其与其他两幅图像相关联，并找出哪一幅具有最大的黑色

Answer 1

如果像素的对应值为零，则认为黑白图像中的Hi。因此，可以说您使用open cv和numpy数组进行处理，我们可以执行以下操作。

import cv2
import numpy as np

img = cv2.imread('pathOfImg',0) #read img as b/w as an numpy array
unique, counts = np.unique(img, return_counts=True)
mapColorCounts = dict(zip(unique, counts))

现在mapColorCounts[0]将是图像中的黑色像素数，此数字越多，图像就越具有黑色。

查找哪个图像最黑

1 个答案: