#!/usr/bin/env python
###############################################################################
# $Id: tolatlong.py 12e021243b6412f39c13e7bf287087359f91c6af 2018-05-06 20:19:59 +1000 Ben Elliston $
#
# Project:  GDAL Python samples
# Purpose:  Script to read coordinate system and geotransformation matrix
#           from input file and report latitude/longitude coordinates for the
#           specified pixel.
# Author:   Andrey Kiselev, dron@remotesensing.org
#
###############################################################################
# Copyright (c) 2003, Andrey Kiselev <dron@remotesensing.org>
# Copyright (c) 2009-2010, Even Rouault <even dot rouault at mines-paris dot org>
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.
###############################################################################

import sys

from osgeo import gdal
from osgeo import osr

# =============================================================================


def Usage():
    print('')
    print('Read coordinate system and geotransformation matrix from input')
    print('file and report latitude/longitude coordinates for the center')
    print('of the specified pixel.')
    print('')
    print('Usage: tolatlong.py pixel line infile')
    print('')
    sys.exit(1)

# =============================================================================


infile = None
pixel = None
line = None

# =============================================================================
# Parse command line arguments.
# =============================================================================
i = 1
while i < len(sys.argv):
    arg = sys.argv[i]

    if pixel is None:
        pixel = float(arg)

    elif line is None:
        line = float(arg)

    elif infile is None:
        infile = arg

    else:
        Usage()

    i = i + 1

if infile is None:
    Usage()
if pixel is None:
    Usage()
if line is None:
    Usage()

# Open input dataset
indataset = gdal.Open(infile, gdal.GA_ReadOnly)

# Read geotransform matrix and calculate ground coordinates
geomatrix = indataset.GetGeoTransform()
X = geomatrix[0] + geomatrix[1] * pixel + geomatrix[2] * line
Y = geomatrix[3] + geomatrix[4] * pixel + geomatrix[5] * line

# Shift to the center of the pixel
X += geomatrix[1] / 2.0
Y += geomatrix[5] / 2.0

# Build Spatial Reference object based on coordinate system, fetched from the
# opened dataset
srs = osr.SpatialReference()
if srs.ImportFromWkt(indataset.GetProjection()) != 0:
    print("ERROR: Cannot import projection '%s'" % indataset.GetProjection())
    sys.exit(1)

srsLatLong = srs.CloneGeogCS()
ct = osr.CoordinateTransformation(srs, srsLatLong)
(lon, lat, height) = ct.TransformPoint(X, Y)

# Report results
print('pixel: %g\t\t\tline: %g' % (pixel, line))
print('latitude: %fd\t\tlongitude: %fd' % (lat, lon))
print('latitude: %s\t\tlongitude: %s' % (gdal.DecToDMS(lat, 'Lat', 2), gdal.DecToDMS(lon, 'Long', 2)))
