python环境下的遥感图像dct水印提取

插入在前面的文章 本文主要是提取算法，详细注释看插入算法

import gdal

import numpy

from skimage import data,img_as_float,img_as_ubyte

import cv2

filename = "f:/bs/band_11_255_0.0075.tif"#插入水印后的图片

dataset = gdal.Open(filename)

im_width = dataset.RasterXSize #获取长

im_height = dataset.RasterYSize #获取宽

im_bands = dataset.RasterCount #获取通道数

im_data = dataset.ReadAsArray(0,0,im_width,im_height)

BLOCK = numpy.zeros([32,32])

M = 3808

N = 238

K = 16

I = numpy.zeros([M,M])

I = im_data[2000:,2000:]

filename = "f:/bs/band_1.tif"

dataset = gdal.Open(filename)

im_width = dataset.RasterXSize #获取长

im_height = dataset.RasterYSize #获取宽

im_bands = dataset.RasterCount #获取通道数

P = dataset.ReadAsArray(0,0,im_width,im_height)

P = P[2000:,2000:]W = numpy.zeros([N,N])

for p in range(238):

for q in range (238):

x = p*K

y = q*K

BLOCK1 = P[x:x+K,y:y+K]

BLOCK2 = I[x:x+K,y:y+K]

BLOCK1 = img_as_float(BLOCK1) #转换unit8为float

BLOCK2 = img_as_float(BLOCK2)

BLOCK1 = cv2.dct(BLOCK1)

BLOCK2 = cv2.dct(BLOCK2)

a = BLOCK1[0][0]/BLOCK2[0][0]-1

if a<0:

W[p][q]=1

else :

W[p][q]=-1

W = img_as_ubyte(W) #转换float为unit8

format = "GTiff"driver = gdal.GetDriverByName(format)

tods = driver.Create("f:/bs/water_wh_1_255_0.0075.bmp",238,238,1,options=["INTERLEAVE = PIXEL"])

tods.WriteRaster(0,0,238,238,W.tostring(),238,238,band_list=[1])

原图：

插入水印后：

水印：

提取出的水印：