MS algorithm for edge detection and transformation to world coordinates
master
kvos 7 years ago
parent ae1f199598
commit 67de70cbad

@ -1 +1,6 @@
This python-based toolbox allows to work with the satellite imagery provided by Google Earth Engine.
This toolbox uses the Google Earth Engine Python API to explore collections of publicly available satellite imagery (Landsat, Sentinel).
It has .py routines to:
- read and preprocess satellite images (cloud masking, contrast stretching)
- pansharpen Landsat 8 images
- extract shorelines with the Marching Squares algorithm

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@ -14,7 +14,7 @@ import pdb
import ee
# other modules
from osgeo import gdal
from osgeo import gdal, ogr, osr
import tempfile
from urllib.request import urlretrieve
import zipfile
@ -28,7 +28,7 @@ import skimage.measure as measure
# import own modules
from utils import *
from functions.utils import *
# Download from ee server function
@ -132,16 +132,30 @@ def read_eeimage(im, polygon, plot_bool):
"""
im_dic = im.getInfo()
# save metadata
im_meta = im_dic.get('properties')
meta = {'timestamp':im_meta['system:time_start'],
'date_acquired':im_meta['DATE_ACQUIRED'],
'geom_rmse_model':im_meta['GEOMETRIC_RMSE_MODEL'],
'gcp_model':im_meta['GROUND_CONTROL_POINTS_MODEL'],
'quality':im_meta['IMAGE_QUALITY_OLI'],
'sun_azimuth':im_meta['SUN_AZIMUTH'],
'sun_elevation':im_meta['SUN_ELEVATION']}
im_bands = im_dic.get('bands')
# delete dimensions key from dictionnary, otherwise the entire image is extracted
for i in range(len(im_bands)): del im_bands[i]['dimensions']
# load panchromatic band
pan_band = [im_bands[7]]
im_pan, crs_pan = load_image(im, polygon, pan_band)
im_pan = im_pan[:,:,0]
# load the multispectral bands (B2,B3,B4,B5,B6) = (blue,green,red,nir,swir1)
ms_bands = [im_bands[1], im_bands[2], im_bands[3], im_bands[4], im_bands[5]]
im_ms_30m, crs_ms = load_image(im, polygon, ms_bands)
# create cloud mask
qa_band = [im_bands[11]]
im_qa, crs_qa = load_image(im, polygon, qa_band)
@ -149,8 +163,27 @@ def read_eeimage(im, polygon, plot_bool):
im_cloud = create_cloud_mask(im_qa)
im_cloud = transform.resize(im_cloud, (im_pan.shape[0], im_pan.shape[1]),
order=0, preserve_range=True, mode='constant').astype('bool_')
# resize the image using bilinear interpolation (order 1)
im_ms = transform.resize(im_ms_30m,(im_pan.shape[0], im_pan.shape[1]),
order=1, preserve_range=True, mode='constant')
# check if -inf values (means out of image) and add to cloud mask
im_inf = np.isin(im_ms[:,:,0], -np.inf)
im_nan = np.isnan(im_ms[:,:,0])
im_cloud = np.logical_or(np.logical_or(im_cloud, im_inf), im_nan)
# get the crs parameters for the image at 15m and 30m resolution
crs = {'crs_15m':crs_pan, 'crs_30m':crs_ms, 'epsg_code':int(pan_band[0]['crs'][5:])}
if plot_bool:
# if there are -inf in the image, set them to 0 before plotting
if sum(sum(np.isin(im_ms_30m[:,:,0], -np.inf).astype(int))) > 0:
idx = np.isin(im_ms_30m[:,:,0], -np.inf)
im_ms_30m[idx,0] = 0; im_ms_30m[idx,1] = 0; im_ms_30m[idx,2] = 0;
im_ms_30m[idx,3] = 0; im_ms_30m[idx,4] = 0
plt.figure()
plt.subplot(221)
@ -161,6 +194,7 @@ def read_eeimage(im, polygon, plot_bool):
plt.imshow(im_ms_30m[:,:,[2,1,0]])
plt.title('RGB')
plt.subplot(223)
plt.imshow(im_ms_30m[:,:,3], cmap='gray')
plt.title('NIR')
@ -171,14 +205,7 @@ def read_eeimage(im, polygon, plot_bool):
plt.show()
# resize the image using bilinear interpolation (order 1)
im_ms = transform.resize(im_ms_30m,(im_pan.shape[0], im_pan.shape[1]),
order=1, preserve_range=True, mode='constant')
# get the crs parameters for the image at 15m and 30m resolution
crs = {'crs_15m':crs_pan, 'crs_30m':crs_ms, 'epsg_code':pan_band[0]['crs']}
return im_pan, im_ms, im_cloud, crs
return im_pan, im_ms, im_cloud, crs, meta
def rescale_image_intensity(im, cloud_mask, prob_high, plot_bool):
@ -517,3 +544,47 @@ def convert_pix2world(points, crs_vec):
raise
return points_converted
def convert_epsg(points, epsg_in, epsg_out):
"""
Converts from one spatial reference to another using the epsg codes
KV WRL 2018
Arguments:
-----------
points: np.ndarray or list of np.ndarray
array with 2 columns (rows first and columns second)
epsg_in: int
epsg code of the spatial reference in which the input is
epsg_out: int
epsg code of the spatial reference in which the output will be
Returns: -----------
points_converted: np.ndarray or list of np.ndarray
converted coordinates
"""
# define input and output spatial references
inSpatialRef = osr.SpatialReference()
inSpatialRef.ImportFromEPSG(epsg_in)
outSpatialRef = osr.SpatialReference()
outSpatialRef.ImportFromEPSG(epsg_out)
# create a coordinates transform
coordTransform = osr.CoordinateTransformation(inSpatialRef, outSpatialRef)
# transform points
if type(points) is list:
points_converted = []
# iterate over the list
for i, arr in enumerate(points):
points_converted.append(np.array(coordTransform.TransformPoints(arr)))
elif type(points) is np.ndarray:
points_converted = np.array(coordTransform.TransformPoints(points))
else:
print('invalid input type')
raise
return points_converted

@ -9,7 +9,8 @@ Contains all the utilities, convenience functions and small functions that do si
import matplotlib.pyplot as plt
import numpy as np
import datetime
import pdb
def ecdf(x):
@ -51,4 +52,3 @@ def compare_images(im1, im2):
ax2 = plt.subplot(122, sharex=ax1, sharey=ax1)
plt.imshow(im2, cmap='gray')
plt.show()

@ -9,191 +9,172 @@ Main code to extract shorelines from Landsat imagery
# Preamble
import ee
from IPython import display
import math
import matplotlib.pyplot as plt
import matplotlib.cm as cm
import numpy as np
import pandas as pd
from datetime import datetime
import pickle
import pdb
import pytz
# image processing modules
import skimage.filters as filters
import skimage.exposure as exposure
import skimage.transform as transform
import sklearn.decomposition as decomposition
import skimage.morphology as morphology
# my modules
from utils import *
from sds1 import *
import skimage.measure as measure
# my functions
import functions.utils as utils
import functions.sds as sds
np.seterr(all='ignore') # raise/ignore divisions by 0 and nans
ee.Initialize()
plot_bool = True
#%% Select images
# parameters
plot_bool = False # if you want the plots
prob_high = 99.9 # upper probability to clip and rescale pixel intensity
min_contour_points = 100 # minimum number of points contained in each water line
output_epsg = 28356 # GDA94 / MGA Zone 56
cloud_threshold = 0.8
# select collection
input_col = ee.ImageCollection('LANDSAT/LC08/C01/T1_RT_TOA')
# filter collection on location (Narrabeen-Collaroy rectangle)
# location (Narrabeen-Collaroy beach)
rect_narra = [[[151.3473129272461,-33.69035274454718],
[151.2820816040039,-33.68206818063878],
[151.27281188964844,-33.74775138989556],
[151.3425064086914,-33.75231878701767],
[151.3473129272461,-33.69035274454718]]];
flt_col = input_col.filterBounds(ee.Geometry.Polygon(rect_narra))
#rect_narra = [[[151.301454, -33.700754],
# [151.311453, -33.702075],
# [151.307237, -33.739761],
# [151.294220, -33.736329],
# [151.301454, -33.700754]]];
# Dates
start_date = '2016-01-01'
end_date = '2016-12-31'
# filter by location
flt_col = input_col.filterBounds(ee.Geometry.Polygon(rect_narra)).filterDate(start_date, end_date)
n_img = flt_col.size().getInfo()
print('Number of images covering Narrabeen:', n_img)
im_all = flt_col.getInfo().get('features')
#%% Extract shorelines
metadata = {'timestamp':[],
'date_acquired':[],
'cloud_cover':[],
'geom_rmse_model':[],
'gcp_model':[],
'quality':[],
'sun_azimuth':[],
'sun_elevation':[]}
skipped_images = np.zeros((n_img,1)).astype(bool)
output_wl = []
# loop through all images
for i in range(n_img):
# find each image in ee database
im = ee.Image(im_all[i].get('id'))
# load image as np.array
im_pan, im_ms, im_cloud, crs, meta = sds.read_eeimage(im, rect_narra, plot_bool)
# if 100% cloud
if sum(sum(im_cloud.astype(int)))/(im_cloud.shape[0]*im_cloud.shape[1]) > cloud_threshold:
skipped_images[i] = True
continue
# store metadata of each image in dict
metadata['timestamp'].append(meta['timestamp'])
metadata['date_acquired'].append(meta['date_acquired'])
metadata['cloud_cover'].append(sum(sum(im_cloud.astype(int)))/(im_cloud.shape[0]*im_cloud.shape[1]))
metadata['geom_rmse_model'].append(meta['geom_rmse_model'])
metadata['gcp_model'].append(meta['gcp_model'])
metadata['quality'].append(meta['quality'])
metadata['sun_azimuth'].append(meta['sun_azimuth'])
metadata['sun_elevation'].append(meta['sun_elevation'])
# rescale intensities
im_ms = sds.rescale_image_intensity(im_ms, im_cloud, prob_high, plot_bool)
im_pan = sds.rescale_image_intensity(im_pan, im_cloud, prob_high, plot_bool)
# pansharpen rgb image
im_ms_ps = sds.pansharpen(im_ms[:,:,[0,1,2]], im_pan, im_cloud, plot_bool)
# add down-sized bands for NIR and SWIR (since pansharpening is not possible)
im_ms_ps = np.append(im_ms_ps, im_ms[:,:,[3,4]], axis=2)
# calculate NDWI
im_ndwi = sds.nd_index(im_ms_ps[:,:,3], im_ms_ps[:,:,1], im_cloud, plot_bool)
# edge detection
wl_pix = sds.find_wl_contours(im_ndwi, im_cloud, min_contour_points, plot_bool)
# convert from pixels to world coordinates
wl_coords = sds.convert_pix2world(wl_pix, crs['crs_15m'])
# convert to output epsg spatial reference
wl = sds.convert_epsg(wl_coords, crs['epsg_code'], output_epsg)
output_wl.append(wl)
print(i)
# generate datetimes
#fmt = '%Y-%m-%d %H:%M:%S %Z%z'
#au_tz = pytz.timezone('Australia/Sydney')
dt = [];
t = metadata['timestamp']
for k in range(len(t)): dt.append(datetime.fromtimestamp(t[k]/1000, tz=pytz.utc))
# save outputs
data = metadata.copy()
data.update({'dt':dt})
data.update({'contours':output_wl})
with open('data_2016.pkl', 'wb') as f:
pickle.dump(data, f)
#%% Load data
#with open('data_2016.pkl', 'rb') as f:
# data = pickle.load(f)
# load backgroud image
i = 0
im = ee.Image(im_all[i].get('id'))
im_pan, im_ms, im_cloud, crs, meta = sds.read_eeimage(im, rect_narra, plot_bool)
im_ms = sds.rescale_image_intensity(im_ms, im_cloud, prob_high, plot_bool)
im_pan = sds.rescale_image_intensity(im_pan, im_cloud, prob_high, plot_bool)
im_ms_ps = sds.pansharpen(im_ms[:,:,[0,1,2]], im_pan, im_cloud, plot_bool)
# select the most recent image of the filtered collection
im = ee.Image(flt_col.sort('SENSING_TIME',False).first())
im_dic = im.getInfo()
image_prop = im_dic.get('properties')
im_bands = im_dic.get('bands')
for i in range(len(im_bands)): del im_bands[i]['dimensions'] # delete the dimensions key
# download the panchromatic band (B8) and QA band (Q11)
pan_band = [im_bands[7]]
im_pan = load_image(im, rect_narra, pan_band)
im_pan = im_pan[:,:,0]
size_pan = im_pan.shape
vec_pan = im_pan.reshape(size_pan[0] * size_pan[1])
qa_band = [im_bands[11]]
im_qa = load_image(im, rect_narra, qa_band)
im_qa = im_qa[:,:,0]
# download the other bands (B2,B3,B4,B5,B6) = (blue,green,red,nir,swir1)
ms_bands = [im_bands[1], im_bands[2], im_bands[3], im_bands[4], im_bands[5]]
im_ms = load_image(im, rect_narra, ms_bands)
size_ms = im_ms.shape
vec_ms = im_ms.reshape(size_ms[0] * size_ms[1], size_ms[2])
# create cloud mask
im_cloud = create_cloud_mask(im_qa)
im_cloud_res = transform.resize(im_cloud, (size_pan[0], size_pan[1]), order=0, preserve_range=True).astype('bool_')
vec_cloud = im_cloud.reshape(im_cloud.shape[0] * im_cloud.shape[1])
vec_cloud_res = im_cloud_res.reshape(size_pan[0] * size_pan[1])
# Plot the RGB image and cloud masks
plt.figure()
ax1 = plt.subplot(121)
plt.imshow(im_ms[:,:,[2,1,0]])
plt.title('RGB')
ax2 = plt.subplot(122)
plt.imshow(im_cloud, cmap='gray')
plt.title('Cloud mask')
#ax3 = plt.subplot(133, sharex=ax1, sharey=ax1)
#plt.imshow(im_cloud_shadow)
#plt.title('Cloud mask shadow')
plt.show()
# Resize multispectral bands (30m) to the size of the pan band (15m) using bilinear interpolation
im_ms_res = transform.resize(im_ms,(size_pan[0], size_pan[1]), order=1, preserve_range=True, mode='constant')
# Rescale image intensity between 0 and 1
prob_high = 99.9
im_ms_adj = rescale_image_intensity(im_ms_res, im_cloud_res, prob_high, plot_bool)
im_pan_adj = rescale_image_intensity(im_pan, im_cloud_res, prob_high, plot_bool)
# Plot adjusted images
plt.figure()
plt.subplot(131)
plt.imshow(im_pan_adj, cmap='gray')
plt.title('PANCHROMATIC (15 m pixel)')
plt.subplot(132)
plt.imshow(im_ms_adj[:,:,[2,1,0]])
plt.title('RGB (30 m pixel)')
plt.show()
plt.subplot(133)
plt.imshow(im_ms_adj[:,:,[3,1,0]])
plt.title('NIR-GB (30 m pixel)')
plt.show()
#%% Pansharpening
im_ms_ps = pansharpen(im_ms_adj[:,:,[0,1,2]], im_pan_adj, im_cloud_res)
# Add resized bands for NIR and SWIR
im_ms_ps = np.append(im_ms_ps, im_ms_adj[:,:,[3,4]], axis=2)
# Plot adjusted images
plt.figure()
plt.subplot(121)
plt.imshow(im_ms_adj[:,:,[2,1,0]])
plt.title('Original RGB')
plt.show()
plt.subplot(122)
plt.imshow(im_ms_ps[:,:,[2,1,0]])
plt.title('Pansharpened RGB')
plt.show()
plt.axis('image')
plt.title('2016 shorelines')
n = len(data['cloud_cover'])
idx_best = []
# remove overlapping images, based on cloud cover
for i in range(n):
date_im = data['date_acquired'][i]
idx = np.isin(data['date_acquired'], date_im)
best = np.where(idx)[0][np.argmin(np.array(data['cloud_cover'])[idx])]
if ~np.isin(best, idx_best):
idx_best.append(best)
point_narra = np.array([342500, 6266990])
plt.figure()
plt.subplot(121)
plt.imshow(im_ms_adj[:,:,[3,1,0]])
plt.title('Original NIR-GB')
plt.show()
plt.subplot(122)
plt.imshow(im_ms_ps[:,:,[3,1,0]])
plt.title('Pansharpened NIR-GB')
plt.show()
im_ndwi_nir = normalized_difference(im_ms_ps[:,:,3], im_ms_ps[:,:,1], im_cloud_res, plot_bool)
vec_ndwi_nir = im_ndwi_nir.reshape(size_pan[0] * size_pan[1])
ndwi_nir = vec_ndwi_nir[~vec_cloud_res]
t_otsu = filters.threshold_otsu(ndwi_nir)
t_min = filters.threshold_minimum(ndwi_nir)
t_mean = filters.threshold_mean(ndwi_nir)
t_li = filters.threshold_li(ndwi_nir)
# try all thresholding algorithms
plt.axis('equal')
plt.grid()
cmap = cm.get_cmap('jet')
colours = cmap(np.linspace(0, 1, num=len(idx_best)))
for i, idx in enumerate(idx_best):
for j in range(len(data['contours'][i])):
if np.any(np.linalg.norm(data['contours'][i][j][:,[0,1]] - point_narra, axis=1) < 200):
plt.plot(data['contours'][i][j][:,0], data['contours'][i][j][:,1],
label=str(data['date_acquired'][i]),
linewidth=2, color=colours[i,:])
plt.figure()
plt.hist(ndwi_nir, bins=300)
plt.plot([t_otsu, t_otsu],[0, 15000], 'r-', label='Otsu threshold')
#plt.plot([t_min, t_min],[0, 15000], 'g-', label='min')
#plt.plot([t_mean, t_mean],[0, 15000], 'y-', label='mean')
#plt.plot([t_li, t_li],[0, 15000], 'm-', label='li')
plt.legend()
plt.show()
plt.figure()
plt.imshow(im_ndwi_nir > t_otsu, cmap='gray')
plt.title('Binary image')
plt.show()
im_bin = im_ndwi_nir > t_otsu
im_open = morphology.binary_opening(im_bin,morphology.disk(1))
im_close = morphology.binary_closing(im_open,morphology.disk(1))
im_bin_coast_in = im_close ^ morphology.erosion(im_close,morphology.disk(1))
im_bin_sl_in = morphology.remove_small_objects(im_bin_coast_in,100,8)
plt.figure()
plt.subplot(121)
plt.imshow(im_close, cmap='gray')
plt.title('morphological closing')
plt.subplot(122)
plt.imshow(im_bin_sl_in, cmap='gray')
plt.title('Water mark')
plt.show()
im_bin_coast_out = morphology.dilation(im_close,morphology.disk(1)) ^ im_close
im_bin_sl_out = morphology.remove_small_objects(im_bin_coast_out,100,8)
# Plot shorelines on top of RGB image
im_rgb_sl = np.copy(im_ms_ps[:,:,[2,1,0]])
im_rgb_sl[im_bin_sl_in,0] = 0
im_rgb_sl[im_bin_sl_in,1] = 1
im_rgb_sl[im_bin_sl_in,2] = 1
im_rgb_sl[im_bin_sl_out,0] = 1
im_rgb_sl[im_bin_sl_out,1] = 0
im_rgb_sl[im_bin_sl_out,2] = 1
plt.figure()
plt.imshow(im_rgb_sl)
plt.title('Pansharpened RGB')
plt.show()

@ -1,76 +0,0 @@
# -*- coding: utf-8 -*-
"""
Created on Thu Mar 1 14:32:08 2018
@author: z5030440
Main code to extract shorelines from Landsat imagery
"""
# Preamble
import ee
import math
import matplotlib.pyplot as plt
import numpy as np
import pdb
# image processing modules
import skimage.filters as filters
import skimage.exposure as exposure
import skimage.transform as transform
import sklearn.decomposition as decomposition
import skimage.morphology as morphology
import skimage.measure as measure
# my modules
from utils import *
from sds import *
np.seterr(all='ignore') # raise/ignore divisions by 0 and nans
ee.Initialize()
# parameters
plot_bool = False # if you want the plots
prob_high = 99.9 # upper probability to clip and rescale pixel intensity
min_contour_points = 100 # minimum number of points contained in each water line
# select collection
input_col = ee.ImageCollection('LANDSAT/LC08/C01/T1_RT_TOA')
# location (Narrabeen-Collaroy beach)
rect_narra = [[[151.3473129272461,-33.69035274454718],
[151.2820816040039,-33.68206818063878],
[151.27281188964844,-33.74775138989556],
[151.3425064086914,-33.75231878701767],
[151.3473129272461,-33.69035274454718]]];
# Dates
start_date = '2016-01-01'
end_date = '2016-12-01'
# filter by location
flt_col = input_col.filterBounds(ee.Geometry.Polygon(rect_narra)).filterDate(start_date, end_date)
n_img = flt_col.size().getInfo()
print('Number of images covering Narrabeen:', n_img)
im_all = flt_col.getInfo().get('features')
output = []
# loop through all images
for i in range(n_img):
# find each image in ee database
im = ee.Image(im_all[i].get('id'))
# load image as np.array
im_pan, im_ms, im_cloud, crs = read_eeimage(im, rect_narra, plot_bool)
# rescale intensities
im_ms = rescale_image_intensity(im_ms, im_cloud, prob_high, plot_bool)
im_pan = rescale_image_intensity(im_pan, im_cloud, prob_high, plot_bool)
# pansharpen rgb image
im_ms_ps = pansharpen(im_ms[:,:,[0,1,2]], im_pan, im_cloud, plot_bool)
# add down-sized bands for NIR and SWIR (since pansharpening is not possible)
im_ms_ps = np.append(im_ms_ps, im_ms[:,:,[3,4]], axis=2)
# calculate NDWI
im_ndwi = nd_index(im_ms_ps[:,:,3], im_ms_ps[:,:,1], im_cloud, plot_bool)
# edge detection
wl_pix = find_wl_contours(im_ndwi, im_cloud, min_contour_points, True)
# convert from pixels to world coordinates
wl_coords = convert_pix2world(wl_pix, crs['crs_15m'])
output.append(wl_coords)
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