動画変換サンプルコード w/ opencv

contrast.py

import numpy as np
import cv2
import time
import sys

start_time = time.time()

input_path = sys.argv[1]

cap = cv2.VideoCapture(input_path)

# width / height / fps
W = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
H = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
fps = cap.get(cv2.CAP_PROP_FPS)
print({'W': W, 'H': H, 'fps': fps})

cap.set(cv2.CAP_PROP_POS_AVI_RATIO, 1)
duration_msec = cap.get(cv2.CAP_PROP_POS_MSEC)
pos_of_frames = cap.get(cv2.CAP_PROP_POS_FRAMES)
num_of_frames = cap.get(cv2.CAP_PROP_FRAME_COUNT)
cap.set(cv2.CAP_PROP_POS_AVI_RATIO, 0)
pos_of_frames2 = cap.get(cv2.CAP_PROP_POS_FRAMES)
print({'duration_msec': duration_msec, 'pos_of_frames': pos_of_frames, 'num_of_frames': num_of_frames, 'pos_of_frames2': pos_of_frames2})


while cap.isOpened():
    ret, image = cap.read()
    if not ret:
        break

    new_image = np.zeros(image.shape, image.dtype)
    alpha = 1.2 # Simple contrast control(1.0-3.0)
    beta = 50    # Simple brightness control(0-100)

    new_image = cv2.convertScaleAbs(image, alpha = alpha, beta = beta)

    # for y in range(image.shape[0]):
    #     for x in range(image.shape[1]):
    #         for c in range(image.shape[2]):
    #             new_image[y,x,c] = np.clip(alpha*image[y,x,c] + beta, 0, 255)

    cv2.imshow('Original Image', image)
    cv2.imshow('New Image', new_image)

    if cv2.waitKey(int(1000/fps)) & 0xFF == ord('q'):
        break

cv2.destroyAllWindows()

end_time = time.time()

print({'elapsed': (end_time - start_time)})

gamma.py

import numpy as np
import cv2
import time
import sys

start_time = time.time()

input_path = sys.argv[1]

cap = cv2.VideoCapture(input_path)

# width / height / fps
W = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
H = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
fps = cap.get(cv2.CAP_PROP_FPS)
print({'W': W, 'H': H, 'fps': fps})

cap.set(cv2.CAP_PROP_POS_AVI_RATIO, 1)
duration_msec = cap.get(cv2.CAP_PROP_POS_MSEC)
pos_of_frames = cap.get(cv2.CAP_PROP_POS_FRAMES)
num_of_frames = cap.get(cv2.CAP_PROP_FRAME_COUNT)
cap.set(cv2.CAP_PROP_POS_AVI_RATIO, 0)
pos_of_frames2 = cap.get(cv2.CAP_PROP_POS_FRAMES)
print({'duration_msec': duration_msec, 'pos_of_frames': pos_of_frames, 'num_of_frames': num_of_frames, 'pos_of_frames2': pos_of_frames2})

# https://docs.opencv.org/master/d3/dc1/tutorial_basic_linear_transform.html
gamma = 0.3
lookUpTable = np.empty((1,256), np.uint8)
for i in range(256):
    lookUpTable[0,i] = np.clip(pow(i / 255.0, gamma) * 255.0, 0, 255)


while cap.isOpened():
    ret, frame = cap.read()
    if not ret:
        break

    res = cv2.LUT(frame, lookUpTable)

    cv2.imshow('New video', res)
    if cv2.waitKey(int(1000/fps)) & 0xFF == ord('q'):
        break

cv2.destroyAllWindows()

end_time = time.time()

print({'elapsed': (end_time - start_time)})