前言

在写波段配准相关代码时经常需要用到tif影像的波段合成和分解，虽然可以用ENVI才处理，但是每次都要打开再设置一些参数有些麻烦，所以本着“独立自主、自力更生”的原则就写了些脚本来处理这个需求。又写了个批量裁剪影像的脚本。这里简单总结归纳一下。

1.波段合并

# coding=utf-8
import sys
import cv2
import functions as fun
import osif __name__ == '__main__':if sys.argv.__len__() >= 2:if sys.argv[1] == 'help' or sys.argv[1] == 'HELP':print("Function description:")print("Join several bands into one file.")print("\nUsage instruction:")print("example.exe [img_dir] [img_type] [out_path]")print("[img_dir]:The input dir that contains band data.")print("[img_type]:The file type of band data,tif or png etc.")print("[out_path]:The filename of joined image.")print("Please note that these band data should have same height and width.")print("\nUsage example:")print("Tool_JoinBands.exe C:\\tif tif C:\\tifout\\joined.tif")os.system('pause')else:img_dir = sys.argv[1]img_type = sys.argv[2]out_path = sys.argv[3]paths, names, files = fun.findAllFiles(img_dir, img_type)bands_data = []# 对于tif文件，统一用gdal打开并输出为tif文件if img_type.endswith('tif') or img_type.endswith('TIF') or img_type.endswith('TIFF') or img_type.endswith('tiff'):for i in range(files.__len__()):band_data = fun.readTifImage(files[i])bands_data.extend(band_data)print("joined " + (i + 1).__str__() + " bands.")print(bands_data.__len__().__str__() + " bands in total.")fun.writeTif(bands_data, out_path)# 对于所有其它类型的文件，如jpg、png等，统一用OpenCV处理else:for i in range(files.__len__()):band_data = cv2.imread(files[i], cv2.IMREAD_GRAYSCALE)bands_data.append(band_data)print("Open image success.")data = cv2.merge((bands_data[0], bands_data[1], bands_data[2]))cv2.imwrite(out_path, data)print("Save image success.")else:print("Unknown mode, input 'yourExeName.exe help' to get help information.")

这里简单介绍下代码。经过波段配准后，不同波段的影像已经实现了对齐，所以通过读取各波段影像然后利用GDAL叠加即可。

2.波段拆分

# coding=utf-8
import sys
import os
import cv2
import functions as funif __name__ == '__main__':if sys.argv.__len__() >= 2:if sys.argv[1] == 'help' or sys.argv[1] == 'HELP':print("Function description:")print("Separate and save different band data in one image file.")print("\nUsage instruction:")print("example.exe [img_path] [out_dir]")print("[img_path]:The filename of input image.")print("[output_dir]:The output dir for different band images.")print("\nUsage example:")print("Tool_SeparateBands.exe C:\\tif\\input.tif C:\\tifout")os.system('pause')else:img_path = sys.argv[1]output_dir = sys.argv[2]# 对于tif文件，统一用gdal打开并输出为tif文件if img_path.endswith('tif') or img_path.endswith('TIF') or img_path.endswith('TIFF') or img_path.endswith('tiff'):bands_data = fun.readTifImage(img_path)for i in range(bands_data.__len__()):fun.writeTif([bands_data[i]], output_dir + os.path.sep + "band_" + i.__str__().zfill(2) + ".tif")print("saved " + (i + 1).__str__() + "/" + bands_data.__len__().__str__())# 对于所有其它类型的文件，如jpg、png等，统一用OpenCV处理else:img = cv2.imread(img_path)print("Open image success.")band_b, band_g, band_r = cv2.split(img)cv2.imwrite(output_dir + os.path.sep + "band_b.png", band_b)cv2.imwrite(output_dir + os.path.sep + "band_g.png", band_g)cv2.imwrite(output_dir + os.path.sep + "band_r.png", band_r)print("Save image success.")else:print("Unknown mode, input 'yourExeName.exe help' to get help information.")

波段拆分与波段合并相反，直接读取一个多波段的tif影像，然后依次保存各波段数据为单独文件即可。

3.影像裁剪

在之前，要想实现影像裁剪的功能需要借助ENVI等软件，但是ENVI等打开比较慢，还要各种设置，比较麻烦。所以直接写了个脚本来方便地实现功能

# coding=utf-8
import sys
import cv2
import functions as fun
import osif __name__ == '__main__':if sys.argv.__len__() >= 2:if sys.argv[1] == 'help' or sys.argv[1] == 'HELP':print("Function description:")print("Select and cut the ROI(region of interest) in a big image file.")print("\nUsage instruction:")print("example.exe [img_path] [out_path] [start_x] [start_y] [x_range] [y_range]")print("[img_path]:The filename of input image.")print("[out_path]:The filename of output image.")print("[start_x]:The x coordinate of ROI's left-top point in big image.")print("[start_y]:The y coordinate of ROI's left-top point in big image.")print("[x_range]:The range of ROI in x direction(width).")print("[y_range]:The range of ROI in y direction(height).")print("\nUsage example:")print("Tool_ResizeIMG.exe C:\\tif\\input.tif C:\\tifout\\roi.tif 100 200 3000 4000")os.system('pause')else:img_path = sys.argv[1]out_path = sys.argv[2]start_x = int(sys.argv[3])start_y = int(sys.argv[4])x_range = int(sys.argv[5])y_range = int(sys.argv[6])# 对于tif文件，统一用gdal打开并输出为tif文件if img_path.endswith('tif') or img_path.endswith('TIF') or img_path.endswith('TIFF') or img_path.endswith('tiff'):bands_data = fun.readTifImageWithWindow(img_path, start_x, start_y, x_range, y_range)fun.writeTif(bands_data, out_path)# 对于所有其它类型的文件，如jpg、png等，统一用OpenCV处理else:bands_data = cv2.imread(img_path)print("Open image success.")bands_data_roi = bands_data[start_y:start_y + y_range, start_x:start_x + x_range, :]cv2.imwrite(out_path, bands_data_roi)print("Save image success.")else:print("Unknown mode, input 'yourExeName.exe help' to get help information.")

影像裁剪实现也相对简单，就是通过设置读取影像范围即可实现对指定区域的裁剪。

4.批量影像裁剪

# coding=utf-8
import sys
import cv2
import functions as fun
import osif __name__ == '__main__':if sys.argv.__len__() >= 2:if sys.argv[1] == 'help' or sys.argv[1] == 'HELP':print("Function description:")print("Select and cut the ROI(region of interest) in big image files(Batch mode).")print("\nUsage instruction:")print("example.exe [img_dir] [img_type] [output_dir] [start_x] [start_y] [x_range] [y_range]")print("[img_dir]:The input dir that contains band data.")print("[img_type]:The file type of band data,tif or png etc.")print("[output_dir]:The output dir for ROI images.")print("[start_x]:The x coordinate of ROI's left-top point in big image.")print("[start_y]:The y coordinate of ROI's left-top point in big image.")print("[x_range]:The range of ROI in x direction(width).")print("[y_range]:The range of ROI in y direction(height).")print("\nUsage example:")print("Tool_ResizeIMG_Batch.exe C:\\tif tif C:\\tifout 100 200 3000 4000")os.system('pause')else:img_dir = sys.argv[1]img_type = sys.argv[2]out_dir = sys.argv[3]start_x = int(sys.argv[4])start_y = int(sys.argv[5])x_range = int(sys.argv[6])y_range = int(sys.argv[7])paths, names, files = fun.findAllFiles(img_dir, img_type)# 对于tif文件，统一用gdal打开并输出为tif文件if img_type.endswith('tif') or img_type.endswith('TIF') or img_type.endswith('TIFF') or img_type.endswith('tiff'):for i in range(files.__len__()):bands_data = fun.readTifImageWithWindow(files[i], start_x, start_y, x_range, y_range)fun.writeTif(bands_data, out_dir + os.path.sep + names[i][:names[i].rfind('.')] + "_cut.tif")print("cutting " + (i + 1).__str__() + "/" + files.__len__().__str__())print('cut finished.')# 对于所有其它类型的文件，如jpg、png等，统一用OpenCV处理else:for i in range(files.__len__()):bands_data = cv2.imread(files[i])bands_data_roi = bands_data[start_y:start_y + y_range, start_x:start_x + x_range, :]cv2.imwrite(out_dir + os.path.sep + "band_" + (i + 1).__str__().zfill(2) + ".jpg", bands_data_roi)print("cutting " + (i + 1).__str__() + "/" + files.__len__())print('cut finished.')else:print("Unknown mode, input 'yourExeName.exe help' to get help information.")

相比于单张影像裁剪，批量裁剪就是多加了个循环，实现了批量操作，也比较简单。

5.模块functions如下:

functions.py

# coding=utf-8
import os
import cv2
import numpy as np
from osgeo import gdal
from gdalconst import *def readTifImage(img_path):data = []# 以只读方式打开遥感影像dataset = gdal.Open(img_path, GA_ReadOnly)if dataset is None:print("Unable to open image file.")return dataelse:print("Open image file success.")bands_num = dataset.RasterCountprint("Image height:" + dataset.RasterYSize.__str__() + " Image width:" + dataset.RasterXSize.__str__())print(bands_num.__str__() + " bands in total.")for i in range(bands_num):# 获取影像的第i+1个波段band_i = dataset.GetRasterBand(i + 1)# 读取第i+1个波段数据band_data = band_i.ReadAsArray(0, 0, band_i.XSize, band_i.YSize)data.append(band_data)print("band " + (i + 1).__str__() + " read success.")return datadef writeTif(bands, path):if bands is None or bands.__len__() == 0:returnelse:# 认为各波段大小相等，所以以第一波段信息作为保存band1 = bands[0]# 设置影像保存大小、波段数img_width = band1.shape[1]img_height = band1.shape[0]num_bands = bands.__len__()# 设置保存影像的数据类型if 'int8' in band1.dtype.name:datatype = gdal.GDT_Byteelif 'int16' in band1.dtype.name:datatype = gdal.GDT_UInt16else:datatype = gdal.GDT_Float32# 创建文件driver = gdal.GetDriverByName("GTiff")dataset = driver.Create(path, img_width, img_height, num_bands, datatype)if dataset is not None:for i in range(bands.__len__()):dataset.GetRasterBand(i + 1).WriteArray(bands[i])print("save image success.")def readTifImageWithWindow(img_path, start_x, start_y, x_range, y_range):data = []# 以只读方式打开遥感影像dataset = gdal.Open(img_path, GA_ReadOnly)if dataset is None:print("Unable to open image file.")return dataelse:print("Open image file success.")bands_num = dataset.RasterCountprint("Image height:" + dataset.RasterYSize.__str__() + " Image width:" + dataset.RasterXSize.__str__())print(bands_num.__str__() + " bands in total.")for i in range(bands_num):# 获取影像的第i+1个波段band_i = dataset.GetRasterBand(i + 1)# 读取第i+1个波段数据band_data = band_i.ReadAsArray(start_x, start_y, x_range, y_range)data.append(band_data)print("band " + (i + 1).__str__() + " read success.")return datadef findAllFiles(root_dir, filter):print("Finding files ends with \'" + filter + "\' ...")separator = os.path.seppaths = []names = []files = []# 遍历for parent, dirname, filenames in os.walk(root_dir):for filename in filenames:if filename.endswith(filter):paths.append(parent + separator)names.append(filename)for i in range(paths.__len__()):files.append(paths[i] + names[i])print (names.__len__().__str__() + " files have been found.")paths.sort()names.sort()files.sort()return paths, names,