图片放大、平移、旋转、透视操作

    1. import cv2 as cv
    2. import numpy as np
    3. from matplotlib import pyplot as plot
    6. def resize():
    7.     img = cv.imread("images/ly.jpg")
    9.     # 缩放
    10.     # cv.INTER_CUBIC放大
    11.     # small = cv.resize(img, None, fx=2, fy=2, interpolation=cv.INTER_LINEAR)
    12.     # big = cv.resize(img, None, fx=2, fy=2, interpolation=cv.INTER_CUBIC)
    13.     # 等价
    14.     height, width = img.shape[:2]
    15.     size = (int(width * 0.5), int(height * 0.4))
    16.     # 缩小
    17.     small = cv.resize(img, size, interpolation=cv.INTER_AREA)
    18.     # 放大
    19.     big = cv.resize(img, (2 * width, 2 * height), interpolation=cv.INTER_CUBIC)
    20.     cv.imshow("small", small)
    21.     cv.imshow("big", big)
    22.     cv.waitKey(0)
    23.     cv.destroyAllWindows()
    26. def warpFfile():
    27.     # 灰色读取
    28.     img = cv.imread("images/ly.jpg", cv.IMREAD_GRAYSCALE)
    29.     # 获取行跟列
    30.     plot.subplot(221)
    31.     plot.imshow(img)
    32.     width, height = img.shape
    33.     # 第一个参数是100 100是向x偏移 100 50是向y偏移50
    34.     M = np.float32([[1, 0, 100], [0, 1, 50]])
    35.     dst = cv.warpAffine(img, M, (width, height))
    36.     plot.subplot(222)
    37.     plot.imshow(img)
    38.     plot.subplot(223)
    39.     plot.imshow(dst)
    40.     plot.show()
    43. # 旋转
    44. def RotationMatrix():
    45.     img = cv.imread("images/ly.jpg", 0)
    46.     width, height = img.shape
    47.     M = cv.getRotationMatrix2D(((width - 1) / 2.0, (height - 1) / 2.0), 90, 1)
    48.     dst = cv.warpAffine(img, M, (width, height))
    49.     cv.imshow("test", dst)
    50.     cv.waitKey(0)
    51.     cv.destroyAllWindows()
    54. # 透视
    55. def toushi():
    56.     # 读取图片
    57.     img = cv.imread("images/ly.jpg")
    58.     image2 = cv.cvtColor(img, cv.COLOR_RGB2BGR)
    59.     plot.imshow(image2)
    60.     # cv.waitKey(0)
    61.     # cv.destroyAllWindows()
    62.     plot.show()
    65. if __name__ == '__main__':
    66.     # warpFfile()
    67.     # RotationMatrix()
    68.     toushi()
    69. import cv2 as cv
    70. import numpy as np
    71. from matplotlib import pyplot as plot
    74. def resize():
    75.     img = cv.imread("images/ly.jpg")
    77.     # 缩放
    78.     # cv.INTER_CUBIC放大
    79.     # small = cv.resize(img, None, fx=2, fy=2, interpolation=cv.INTER_LINEAR)
    80.     # big = cv.resize(img, None, fx=2, fy=2, interpolation=cv.INTER_CUBIC)
    81.     # 等价
    82.     height, width = img.shape[:2]
    83.     size = (int(width * 0.5), int(height * 0.4))
    84.     # 缩小
    85.     small = cv.resize(img, size, interpolation=cv.INTER_AREA)
    86.     # 放大
    87.     big = cv.resize(img, (2 * width, 2 * height), interpolation=cv.INTER_CUBIC)
    88.     cv.imshow("small", small)
    89.     cv.imshow("big", big)
    90.     cv.waitKey(0)
    91.     cv.destroyAllWindows()
    94. def warpFfile():
    95.     # 灰色读取
    96.     img = cv.imread("images/ly.jpg", cv.IMREAD_GRAYSCALE)
    97.     # 获取行跟列
    98.     plot.subplot(221)
    99.     plot.imshow(img)
    100.     width, height = img.shape
    101.     # 第一个参数是100 100是向x偏移 100 50是向y偏移50
    102.     M = np.float32([[1, 0, 100], [0, 1, 50]])
    103.     dst = cv.warpAffine(img, M, (width, height))
    104.     plot.subplot(222)
    105.     plot.imshow(img)
    106.     plot.subplot(223)
    107.     plot.imshow(dst)
    108.     plot.show()
    111. # 旋转
    112. def RotationMatrix():
    113.     img = cv.imread("images/ly.jpg", 0)
    114.     width, height = img.shape
    115.     M = cv.getRotationMatrix2D(((width - 1) / 2.0, (height - 1) / 2.0), 90, 1)
    116.     dst = cv.warpAffine(img, M, (width, height))
    117.     cv.imshow("test", dst)
    118.     cv.waitKey(0)
    119.     cv.destroyAllWindows()
    122. # 透视
    123. def toushi():
    124.     img = cv.imread('images/ly.jpg', 0)
    125.     image2 = cv.cvtColor(img, cv.COLOR_BGR2RGB)
    126.     # 左上 右上 左下 右下
    127.     pts1 = np.float32([[150, 150], [450, 150], [150, 800], [450, 800]])
    128.     # 第一个参数是值 第一个点的展示位置0,0表示左上角 300,0表示右上角依次类推
    129.     pts2 = np.float32([[0, 0], [300, 0], [0, 300], [300, 300]])
    130.     M = cv.getPerspectiveTransform(pts1, pts2)
    131.     dst = cv.warpPerspective(image2, M, (300, 300))
    132.     plot.subplot(121), plot.imshow(image2), plot.title('Input')
    133.     plot.subplot(122), plot.imshow(dst), plot.title('Output')
    134.     plot.show()
    137. if __name__ == '__main__':
    138.     # warpFfile()
    139.     # RotationMatrix()
    140.     toushi()