66 lines
2.2 KiB
Python
66 lines
2.2 KiB
Python
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"""background.py
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This code implements the Background class for the TensorRT MODNet
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demo. The Background class could generate background images from
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either a still image, a video file or nothing (pure black bg).
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"""
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import numpy as np
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import cv2
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class Background():
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"""Backgrounf class which supports one of the following sources:
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1. Image (jpg, png, etc.) file, repeating indefinitely
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2. Video file, looping forever
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3. None -> black background
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# Arguments
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src: if not spcified, use black background; else, src should be
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a filename of an image (jpg/png) or video (mp4/ts)
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width & height: width & height of the output background image
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"""
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def __init__(self, src, width, height, demo_mode=False):
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self.src = src
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self.width = width
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self.height = height
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self.demo_mode = demo_mode
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if not src: # empty source: black background
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self.is_video = False
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self.bg_frame = np.zeros((height, width, 3), dtype=np.uint8)
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elif not isinstance(src, str):
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raise ValueError('bad src')
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elif src.endswith('.jpg') or src.endswith('.png'):
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self.is_video = False
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self.bg_frame = cv2.resize(cv2.imread(src), (width, height))
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assert self.bg_frame is not None and self.bg_frame.ndim == 3
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elif src.endswith('.mp4') or src.endswith('.ts'):
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self.is_video = True
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self.cap = cv2.VideoCapture(src)
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assert self.cap.isOpened()
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else:
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raise ValueError('unknown src')
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def read(self):
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"""Read a frame from the Background object."""
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if self.is_video:
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_, frame = self.cap.read()
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if frame is None:
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# assume end of video file has been reached, so loop around
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self.cap.release()
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self.cap = cv2.VideoCapture(self.src)
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_, frame = self.cap.read()
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return cv2.resize(frame, (self.width, self.height))
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else:
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return self.bg_frame.copy()
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def __del__(self):
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if self.is_video:
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try:
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self.cap.release()
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except:
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pass
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