对Python3+gdal 读取tiff格式数据的实例讲解

时间:2022-09-13 23:10:11

1、遇到的问题:numpy版本

im_data = dataset.ReadAsArray(0,0,im_width,im_height)#获取数据 这句报错

升级numpy:pip install -U numpy 但是提示已经是最新版本

解决:卸载numpy 重新安装

2.直接从压缩包中读取tiff图像

参考:http://gdal.org/gdal_virtual_file_systems.html#gdal_virtual_file_systems_vsizip

当前情况是2层压缩: /'/vsitar/C:/Users/summer/Desktop/a_PAN1.tiff'

3.读tiff

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def readTif(fileName):
    
    merge_img = 0
    driver = gdal.GetDriverByName('GTiff')
    driver.Register()
 
    dataset = gdal.Open(fileName)
    if dataset == None:
        print(fileName+ "掩膜失败,文件无法打开")
        return
    im_width = dataset.RasterXSize #栅格矩阵的列数
    print('im_width:', im_width)
 
    im_height = dataset.RasterYSize #栅格矩阵的行数
    print('im_height:', im_height)
    im_bands = dataset.RasterCount #波段数
    im_geotrans = dataset.GetGeoTransform()#获取仿射矩阵信息
    im_proj = dataset.GetProjection()#获取投影信息
    
 
    if im_bands == 1:
        band = dataset.GetRasterBand(1)
        im_data = dataset.ReadAsArray(0,0,im_width,im_height) #获取数据
        cdata = im_data.astype(np.uint8)
        merge_img = cv2.merge([cdata,cdata,cdata])
 
        cv2.imwrite('C:/Users/summer/Desktop/a.jpg', merge_img)
#
    elif im_bands == 4:
    #   # im_data = dataset.ReadAsArray(0,0,im_width,im_height)#获取数据
    #   # im_blueBand = im_data[0,0:im_width,0:im_height] #获取蓝波段
    #   # im_greenBand = im_data[1,0:im_width,0:im_height] #获取绿波段
    #   # im_redBand = im_data[2,0:im_width,0:im_height] #获取红波段
    #   # # im_nirBand = im_data[3,0:im_width,0:im_height] #获取近红外波段
    #   # merge_img=cv2.merge([im_redBand,im_greenBand,im_blueBand])
 
    #   # zeros = np.zeros([im_height,im_width],dtype = "uint8")
 
    #   # data1 = im_redBand.ReadAsArray
 
    #   band1=dataset.GetRasterBand(1)
    #   band2=dataset.GetRasterBand(2)
    #   band3=dataset.GetRasterBand(3)
    #   band4=dataset.GetRasterBand(4)
    
        data1=band1.ReadAsArray(0,0,im_width,im_height).astype(np.uint16) #r #获取数据
        data2=band2.ReadAsArray(0,0,im_width,im_height).astype(np.uint16) #g #获取数据
        data3=band3.ReadAsArray(0,0,im_width,im_height).astype(np.uint16) #b #获取数据
        data4=band4.ReadAsArray(0,0,im_width,im_height).astype(np.uint16) #R #获取数据
    #   print(data1[1][45])
    #   output1= cv2.convertScaleAbs(data1, alpha=(255.0/65535.0))
    #   print(output1[1][45])
    #   output2= cv2.convertScaleAbs(data2, alpha=(255.0/65535.0))
    #   output3= cv2.convertScaleAbs(data3, alpha=(255.0/65535.0))
 
        merge_img1 = cv2.merge([output3,output2,output1]) #B G R
        
        cv2.imwrite('C:/Users/summer/Desktop/merge_img1.jpg', merge_img1)

4.图像裁剪:

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import cv2
import numpy as np
import os
 
tiff_file = './try_img/2.tiff'
save_folder = './try_img_re/'
if not os.path.exists(save_folder):
    os.makedirs(save_folder)
 
tif_img = cv2.imread(tiff_file)
width, height, channel = tif_img.shape
# print height, width, channel : 6908 7300 3
threshold = 1000
overlap = 100
 
step = threshold - overlap
x_num = width/step + 1
y_num = height/step + 1
print x_num, y_num
 
N = 0
yj = 0
 
for xi in range(x_num):
    for yj in range(y_num):
    # print xi
        if yj <= y_num:
            print yj
            x = step*xi
      y = step*yj
 
      wi = min(width,x+threshold)
      hi = min(height,y+threshold)
      # print wi , hi
 
      if wi-x < 1000 and hi-y < 1000:
        im_block = tif_img[wi-1000:wi, hi-1000:hi]
 
      elif wi-x > 1000 and hi-y < 1000:
        im_block = tif_img[x:wi, hi-1000:hi]
 
      elif wi-x < 1000 and hi-y > 1000:
        im_block = tif_img[wi-1000:wi, y:hi]
 
        else:
        im_block = tif_img[x:wi,y:hi]
        
      cv2.imwrite(save_folder + 'try' + str(N) + '.jpg', im_block)
      N += 1

以上这篇对Python3+gdal 读取tiff格式数据的实例讲解就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持服务器之家。

原文链接:https://blog.csdn.net/summermaoz/article/details/78346929