python

超轻量级php框架startmvc

对Python3+gdal 读取tiff格式数据的实例讲解

更新时间:2020-06-14 00:24:01 作者:startmvc
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

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 = 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:


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脚本之家。

Python3 gdal tiff