python对yuv图像裁剪

Posted 2022-12-14 神遁克里苏

首先读取yuv图像，从图像的命名中读出图像的长和宽，可能要跟你的yuv文件命名方式来做修改。

这是我的yuv图像的命名方式。

达到长和宽之后就可以读取图像的像素值了，我这里设置的是裁剪成40的倍数，这两句是得到裁剪后的长和宽。

 Height_Y = Height_Y // cropc * cropc
 Width_Y = Width_Y // cropc * cropc

裁剪

     current_Y = Y[0:Height_Y, 0: Width_Y ]
     current_U = U[0:Height_Y // 2, 0:Width_Y // 2 ]
     current_V = V[0:Height_Y // 2, 0:Width_Y // 2 ]

将 current_Y转换为list，方便存储

     list_y = list(current_Y.reshape((Height_Y * Width_Y)))
     list_u = list(current_U.reshape(((Height_Y // 2 )* (Width_Y  // 2))))
     list_v = list(current_V.reshape(((Height_Y // 2 ) * (Width_Y  // 2))))

存储

   outpath='D:/NN/265_cut/37_wo/'+str(num).rjust(4,'0')+'_'+str(Width_Y)+'x'+str(Height_Y)+'.yuv'
    with open(outpath, 'wb+') as ff:
        ff.write(np.array(list_y, dtype=np.uint8).tobytes())
        ff.write(np.array(list_u, dtype=np.uint8).tobytes())
        ff.write(np.array(list_v, dtype=np.uint8).tobytes())

完整代码如下：

import numpy as np


cropc=40

rootpath='C:/valid/valid_yuv'

for i in os.listdir(rootpath):
     subfile = rootpath + '/' + i
     size = i.split('.')[0]
     num =size.split('_')[0]
     size=size.split('_')[1]
     width = size.split('x')[0]
     Width_Y = int(width)
     height = size.split('x')[1]
     Height_Y = int(height)



     fp1 = open(subfile, 'rb')
     Y = np.frombuffer(fp1.read(Height_Y * Width_Y * 2 // 2), np.uint8).reshape((Height_Y , Width_Y))
     U = np.frombuffer(fp1.read(Height_Y * Width_Y // 2 // 2), np.uint8).reshape((Height_Y // 2 , Width_Y // 2))
     V = np.frombuffer(fp1.read(Height_Y * Width_Y // 2 // 2), np.uint8).reshape((Height_Y // 2 ,Width_Y // 2))



     Height_Y = Height_Y // cropc * cropc
     Width_Y = Width_Y // cropc * cropc

     current_Y = Y[0:Height_Y, 0: Width_Y ]
     current_U = U[0:Height_Y // 2, 0:Width_Y // 2 ]
     current_V = V[0:Height_Y // 2, 0:Width_Y // 2 ]


     list_y = list(current_Y.reshape((Height_Y * Width_Y)))
     list_u = list(current_U.reshape(((Height_Y // 2 )* (Width_Y  // 2))))
     list_v = list(current_V.reshape(((Height_Y // 2 ) * (Width_Y  // 2))))


     outpath='D:/NN/265_cut/37_wo/'+str(num).rjust(4,'0')+'_'+str(Width_Y)+'x'+str(Height_Y)+'.yuv'
     with open(outpath, 'wb+') as ff:
        ff.write(np.array(list_y, dtype=np.uint8).tobytes())
        ff.write(np.array(list_u, dtype=np.uint8).tobytes())
        ff.write(np.array(list_v, dtype=np.uint8).tobytes())