用python gdal包处理tif遥感图像
先讲讲gdal包的安装，先前轻敌，以为pip就安装了，现在发现这是不可能的事情，只能用conda安装，也是这么久第一次遇到的。
1.gdal安装
conda install gdal
安装前，会自动下载安装一堆conda包
The following packages will be downloaded: package | build ---------------------------|----------------- aws-c-common-0.4.57 | ha925a31_1 147 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main aws-c-event-stream-0.1.6 | hd77b12b_5 26 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main aws-checksums-0.1.9 | ha925a31_0 50 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main aws-sdk-cpp-1.8.185 | hd77b12b_0 2.5 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main blas-1.0 | mkl 6 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main bzip2-1.0.8 | he774522_0 113 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main ca-certificates-2021.10.26 | haa95532_2 115 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main certifi-2021.10.8 | py37haa95532_2 152 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main cfitsio-3.470 | he774522_6 512 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main curl-7.80.0 | h2bbff1b_0 137 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main expat-2.4.1 | h6c2663c_2 201 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main freexl-1.0.6 | h2bbff1b_0 51 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main gdal-3.0.2 | py37hb978731_1 1.0 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main geos-3.8.0 | h33f27b4_0 905 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main geotiff-1.6.0 | h5770a2b_0 128 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main hdf4-4.2.13 | h712560f_2 1.3 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main hdf5-1.10.6 | h7ebc959_0 7.9 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main icc_rt-2019.0.0 | h0cc432a_1 6.0 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main intel-openmp-2021.4.0 | haa95532_3556 2.2 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main jpeg-9d | h2bbff1b_0 283 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main kealib-1.4.14 | hde4a422_1 140 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main krb5-1.19.2 | h5b6d351_0 697 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main libcurl-7.80.0 | h86230a5_0 295 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main libgdal-3.0.2 | ha1b3edf_1 7.0 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main libiconv-1.15 | h1df5818_7 626 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main libnetcdf-4.6.1 | hf59b723_4 501 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main libpng-1.6.37 | h2a8f88b_0 333 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main libpq-12.9 | hb652d5d_1 2.7 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main libspatialite-4.3.0a | h7ffb84d_0 2.3 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main libssh2-1.9.0 | h7a1dbc1_1 215 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main libtiff-4.2.0 | hd0e1b90_0 786 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main libxml2-2.9.12 | h0ad7f3c_0 1.5 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main lz4-c-1.9.3 | h2bbff1b_1 132 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main m2w64-expat-2.1.1 | 2 160 KB m2w64-gcc-libgfortran-5.3.0| 6 340 KB m2w64-gcc-libs-5.3.0 | 7 518 KB m2w64-gcc-libs-core-5.3.0 | 7 213 KB m2w64-gettext-0.19.7 | 2 4.2 MB m2w64-gmp-6.1.0 | 2 689 KB m2w64-libiconv-1.14 | 6 1.5 MB m2w64-libwinpthread-git-5.0.0.4634.697f757| 2 30 KB m2w64-xz-5.2.2 | 2 395 KB mkl-2021.4.0 | haa95532_640 114.9 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main mkl-service-2.4.0 | py37h2bbff1b_0 49 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main mkl_fft-1.3.1 | py37h277e83a_0 135 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main mkl_random-1.2.2 | py37hf11a4ad_0 216 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main msys2-conda-epoch-20160418 | 1 2 KB numpy-1.21.2 | py37hfca59bb_0 24 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main numpy-base-1.21.2 | py37h0829f74_0 4.4 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main openjpeg-2.4.0 | h4fc8c34_0 219 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main openssl-1.1.1m | h2bbff1b_0 4.8 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main postgresql-12.9 | hb652d5d_1 13.5 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main proj-6.2.1 | h9f7ef89_0 7.9 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main six-1.16.0 | pyhd3eb1b0_0 18 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main tiledb-2.2.9 | hf7ce2e6_0 948 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main xerces-c-3.2.3 | ha925a31_0 2.8 MB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main xz-5.2.5 | h62dcd97_0 244 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main zlib-1.2.11 | h8cc25b3_4 112 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main zstd-1.4.9 | h19a0ad4_0 478 KB https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main
2.编写tif2jpg函数
#!/usr/bin/python # -*- coding: UTF-8 -*- """ @author:livingbody @file:tif2jpg.py @time:2022/01/21 """ import cv2 import numpy as np from osgeo import gdal def tif2jpg(tif_path, lower_percent=0.6, higher_percent=99.4): ds = gdal.Open(tif_path, gdal.GA_ReadOnly) origin_label = np.empty(shape=(ds.RasterYSize, ds.RasterXSize, ds.RasterCount), dtype='float64') for i in range(ds.RasterCount): band = ds.GetRasterBand(ds.RasterCount - i) origin_label[:, :, i] = band.ReadAsArray() label = np.zeros_like(origin_label, dtype='uint8') for i in range(origin_label.shape[2]): l, h = 0, 255 l_cut, h_cut = np.percentile(origin_label[:, :, i], lower_percent), \ np.percentile(origin_label[:, :, i], higher_percent) channel = l + (origin_label[:, :, i] - l_cut) * (h - l) / (h_cut - l_cut) channel[channel < l] = l channel[channel > h] = h label[:, :, i] = channel return label if __name__ == '__main__': cv2.imwrite('1.jpg', tif2jpg('000025_GF.tif'))
3.gdal库引入及使用效果
from osgeo import gdal如果正常结束，就没有问题了。
3.AI Studio中gdal库的安装和使用
- 用AI Studio
基础版环境，不要用至尊版，会出很奇怪的问题； - 用conda安装，不要用pip；
- 安装到
/home/aistudio/文件夹下，利用AI Studio的文件保存，避免每次都重新安装GDAL，安装挺耗时的，大概7分钟； - 安装命令带上
-y参数，避免安装过程中需要交互，导致安装被阻塞。
具体安装如下：
# 安装 !mkdir /home/aistudio/extlib !conda install --prefix=/home/aistudio/extlib gdal -y # 引入 import sys sys.path.append('/home/aistudio/extlib/lib/python3.6/site-packages')
4.gdal库引入及使用效果
生成tif图
import matplotlib.pyplot as plt import numpy as np %matplotlib inline driver = gdal.GetDriverByName("GTiff") data = driver.Create("1.tif", xsize=300,ysize=200,bands=3) data.FlushCache() data = None img = plt.imread("1.tif") plt.imshow(img)
生成tif图
import numpy as np import matplotlib.pyplot as plt driver = gdal.GetDriverByName("GTiff") data = driver.Create("1.tif", ysize=200,xsize=300,bands=3) for i in range(3): outband=data.GetRasterBand(i+1) in_array = np.random.rand(200,300)*255 outband.WriteArray(in_array.astype(int)) data.FlushCache() data = None img = plt.imread("1.tif") plt.imshow(img)
