我想在播放视频时生成热图,基本上我想显示人群密度。我不知道该怎么做,我现在正在这样做,它会在处理完整个视频后计算热图,我只是想让它直播,就像视频正在播放并且颜色在不同的地方传播一样。
import numpy as np
import cv2
class Motion:
def __init__(self):
print("Motion Detection Object Created")
# input file name of video
self.inname = 'data.mp4'
# file name to save
self.outname = "C:/Heatmap"
def prep(self):
# just read the first frame to get height and width
cap = cv2.VideoCapture(self.inname)
ret, self.orig_image = cap.read()
width = np.size(self.orig_image, 1)
height = np.size(self.orig_image, 0)
frame_size = (height, width)
# make accumulator image of the same size
self.accumulator = np.zeros((height, width), np.float32) # 32 bit accumulator
def run(self):
cap = cv2.VideoCapture(self.inname)
fgbg = cv2.createBackgroundSubtractorMOG2(varThreshold=1000, detectShadows=True)
#print(fgbg[0])
while (1):
ret, frame = cap.read()
#print(frame)
if not ret:
break
fgmask = fgbg.apply(frame)
self.accumulator = self.accumulator + fgmask
def write(self):
self.ab = cv2.convertScaleAbs(255 - np.array(self.accumulator, 'uint8'))
# only get reasonable high values, above mean
ret, self.acc_thresh = cv2.threshold(self.ab, self.ab.mean(), 255, cv2.THRESH_TOZERO)
# make a color map
acc_col = cv2.applyColorMap(self.acc_thresh, cv2.COLORMAP_RAINBOW)
cv2.imwrite(str(self.outname + "/heatmap.jpg"), acc_col)
# add to original frame
backg = cv2.addWeighted(np.array(acc_col, "uint8"), 0.45, self.orig_image, 0.55, 0)
cv2.imwrite(str(self.outname + "/heatmap_background.jpg"), backg)
# MAIN ENTRY POINT
if __name__ == "__main__":
motionVid = Motion()
motionVid.prep()
motionVid.run()
motionVid.write()
最佳答案
在你的 write
函数中,尝试添加这个:
VideoWriter video("output.avi",CV_FOURCC('M','J','P','G'),10,Size(frame_width,frame_height));
此处 frame_width
= 宽度 & frame_height
= 高度
您可以在 OpenCV 文档中获取用于视频压缩的编解码器列表。
关于python - OpenCV python 中的实时热图生成,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/43767445/