1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
|
#!/usr/bin/env python3
# This program is a direct translation of the sample program
# "write_bands.c" bundled with the EPR-API distribution.
#
# Source code of the C program is available at:
# https://github.com/bcdev/epr-api/blob/master/src/examples/write_bands.c
import os
import sys
import epr
def write_raw_image(output_dir, product, band_name):
"""Generate the ENVI binary pattern image file for an actual DS.
The first parameter is the output directory path.
"""
# Build ENVI file path, DS name specifically
image_file_path = os.path.join(output_dir, band_name + ".raw")
band = product.get_band(band_name)
source_w = product.get_scene_width()
source_h = product.get_scene_height()
source_step_x = 1
source_step_y = 1
raster = band.create_compatible_raster(
source_w, source_h, source_step_x, source_step_y
)
print(f"Reading band {band_name!r}...")
raster = band.read_raster(0, 0, raster)
with open(image_file_path, "wb") as out_stream:
for line in raster.data:
out_stream.write(line.tostring())
# or better: raster.data.tofile(out_stream)
print(f"Raw image data successfully written to {image_file_path!r}.")
print(
f"C data type is {epr.data_type_id_to_str(raster.data_type)!r}, "
f"element size {raster.get_elem_size()} byte(s), "
f"raster size is {raster.get_width()} x {raster.get_height()} pixels."
)
def main(*argv):
"""A program for converting producing ENVI raster information from
dataset.
It generates as many raster as there are dataset entrance parameters.
Call::
$ python3 write_bands.py <envisat-product>
<output directory for the raster file>
<dataset name 1>
[<dataset name 2> ... <dataset name N>]
Example::
$ python3 write_bands.py \
MER_RR__1PNPDK20020415_103725_000002702005_00094_00649_1059.N1 \
. latitude
"""
if not argv:
argv = sys.argv
if len(argv) <= 3:
print(
"""Usage:
python3 write_bands.py <envisat-product> <output-dir> <dataset-name-1>
[<dataset-name-2> ... <dataset-name-N>]
where envisat-product is the input filename and output-dir is the
output directory and dataset-name-1 is the name of the first band
to be extracted (mandatory) and dataset-name-2 ... dataset-name-N
are the names of further bands to be extracted (optional)
Example:
python3 write_bands MER_RR__2P_TEST.N1 . latitude
"""
)
sys.exit(1)
product_file_path = argv[1]
output_dir_path = argv[2]
# Open the product; the argument is the path to product the data file
with epr.open(product_file_path) as product:
for band_name in argv[3:]:
write_raw_image(output_dir_path, product, band_name)
if __name__ == "__main__":
main()
|
