GDAL实现标准差拉伸渲染影像

import os
from sys import path
from osgeo import gdal
from osgeo import osr
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.colors as mpc
import argparse


def stdStretch(imgFile, colorList, flag, outPath):
    # imgFile 影像
    # colorList 色带参数
    # flag=True 将数据投影到3857坐标系进行显示
    # flag=False 将数据按原坐标系进行显示
    gdal.AllRegister()
    ds = gdal.Open(imgFile)
    if flag:

        dsrs = osr.SpatialReference()
        dsrs.ImportFromEPSG(3857)
        vrt_ds = gdal.AutoCreateWarpedVRT(
            ds, None, dsrs.ExportToWkt(), gdal.GRA_Bilinear)
        band = gdal.Dataset.GetRasterBand(vrt_ds, 1)
    else:
        band = gdal.Dataset.GetRasterBand(ds, 1)
    array = gdal.Band.ReadAsArray(band)
    avg = np.nanmean(array)
    std = np.nanstd(array)
    # 默认按2.5倍标准差进行拉伸
    v_max = avg+2.5*std
    v_min = avg-2.5*std
    norm = plt.Normalize(v_min, v_max)
    colors = colorList
    cm = mpc.LinearSegmentedColormap.from_list(\'colormap\', colors, 512)
    plt.imshow(array, cm, norm)
    plt.axis(\'off\')
    plt.subplots_adjust(bottom=0, top=1, left=0, right=1, hspace=0, wspace=0)
    plt.colorbar()
    outname = os.path.basename(imgFile)
    outname = outname.replace(outname[outname.rindex(\'.\'):], \'.png\')
    outname = os.path.join(outPath, outname)
    plt.savefig(outname, transparent=True, dpi=100)
    plt.close()


# 封装为命令行工具 批量处理目录下的影像
if __name__ == \'__main__\':
    parser = argparse.ArgumentParser(\'标准差拉伸渲染影像\')
    parser.add_argument(
        \'inputPath\', type=str, help=\'The directory  stores the images or a image file to process!\')
    parser.add_argument(\'colorList\', type=str,
                        help=\'Color map used in render!\')
    parser.add_argument(\'outPath\', type=str,
                        help=\'The directory stores the result!\')
    parser.add_argument(
        \'flag\', type=bool, help=\'A flag which indicates whether the image should be prjected to epsg3857!\')
    parser.add_argument(\'extension\',type=str,help=\'The extension of image file to be processed!\',default=None)
    args=parser.parse_args()
    
    inputPath=args.inputPath
    colors=args.colorList.split(\',\')
    outPath=args.outPath
    flag=args.flag
    extension=args.extension
    # extension=None 则处理目录下的所有影像

    if os.path.isfile(inputPath):
        # 处理单张影像
        stdStretch(inputPath,colors,flag,outPath)
    else:
        # 处理整个目录
        imgFiles=os.listdir(inputPath)
        for imgFile in imgFiles:
            if not(extension) or imgFile.endswith(extension):
                stdStretch(os.path.join(inputPath,imgFile),colors,flag,outPath)
    # colors = \'#0000FF, #3B7FFF, #00FFFF,#B4FF91, #FFFF00, #FF9100, #FF0000\'
    print(\'finished!\')

调用方式

user@DESKTOP-IFIB8V0 MINGW64 /i/毕业设计整理/LST
$ python color.py --help
usage: 标准差拉伸渲染影像 [-h] inputPath colorList outPath flag extension

positional arguments:
  inputPath   The directory stores the images or a image file to process!
  colorList   Color map used in render!
  outPath     The directory stores the result!
  flag        A flag which indicates whether the image should be prjected to epsg3857!
  extension   The extension of image file to be processed!

optional arguments:
  -h, --help  show this help message and exit
(base) 

渲染结果