遥感影像32位转8位（python）

# -*- coding: utf-8 -*-
import os, sys, time
import numpy as np
from osgeo import ogr
from osgeo import gdal
from osgeo import gdal_array as ga

def stretch_n(bands, img_min, img_max, lower_percent=0, higher_percent=100):
    """
    :param bands:  目标数据，numpy格式
    :param img_min:   目标位深的最小值，以8bit为例，最大值为255， 最小值为0
    :param img_max:    目标位深的最大值
    :return:
    """
    out = np.zeros_like(bands).astype(np.float32)
    a = img_min
    b = img_max
    c = np.percentile(bands[:, :], lower_percent)
    d = np.percentile(bands[:, :], higher_percent)
    t = a + (bands[:, :] - c) * (b - a) / (d - c)
    t[t < a] = a
    t[t > b] = b
    out[:, :] = t
    return out

def read_img(filename):
    dataset=gdal.Open(filename)

    im_width = dataset.RasterXSize
    im_height = dataset.RasterYSize

    im_geotrans = dataset.GetGeoTransform()
    im_proj = dataset.GetProjection()
    im_data = dataset.ReadAsArray(0,0,im_width,im_height)

    del dataset 
    return im_proj,im_geotrans,im_width, im_height,im_data


def write_img(filename, im_proj, im_geotrans, im_data):
    if 'int8' in im_data.dtype.name:
        datatype = gdal.GDT_Byte
    elif 'int16' in im_data.dtype.name:
        datatype = gdal.GDT_UInt16
    else:
        datatype = gdal.GDT_Float32

    if len(im_data.shape) == 3:
        im_bands, im_height, im_width = im_data.shape
    else:
        im_bands, (im_height, im_width) = 1,im_data.shape 

    driver = gdal.GetDriverByName("GTiff")
    dataset = driver.Create(filename, im_width, im_height, im_bands, datatype)

    dataset.SetGeoTransform(im_geotrans)
    dataset.SetProjection(im_proj)

    if im_bands == 1:
        dataset.GetRasterBand(1).WriteArray(im_data)
    else:
        for i in range(im_bands):
            dataset.GetRasterBand(i+1).WriteArray(im_data[i])

    del dataset


if __name__ == "__main__":
    origin_32 = ['train_image1.tif', 'train_image2.tif']
    target_path = 'target_8'
    mkdir(target_path)
    output_8 = [os.path.join(target_path, subPath) for subPath in origin_32]
    for input, output in zip(origin_32, output_8):
        im_proj, im_geotrans, im_width, im_height, im_data = read_img(input)
        out = stretch_n(im_data, 0, 255)
        write_img(output, im_proj, im_geotrans, out.astype(np.int8))

本文地址：https://blog.csdn.net/weixin_42990464/article/details/107152799