对Python3+gdal 读取tiff格式数据的实例讲解

Python  /  管理员 发布于 7年前   303

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

def readTif(fileName):merge_img = 0driver = gdal.GetDriverByName('GTiff')driver.Register() dataset = gdal.Open(fileName)if dataset == None:print(fileName+ "掩膜失败，文件无法打开")returnim_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 Rcv2.imwrite('C:/Users/summer/Desktop/merge_img1.jpg', merge_img1)

4.图像裁剪：

import cv2import numpy as npimport 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 3threshold = 1000overlap = 100 step = threshold - overlapx_num = width/step + 1y_num = height/step + 1print x_num, y_num N = 0yj = 0  for xi in range(x_num):for yj in range(y_num):# print xiif yj <= y_num:print yjx = 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。