Iss14 (#30)

* Fixing the issue with subsetting LandSat GeoTIFF files

Subsetting of LandSat GeoTIFF files failed because the projection of
LandSat files is different from lat/lon values usually given as input.

Therefore, a function was added to transform the lat/lon values to
the projection of LandSat data (derived automatically)

Furthermore, subsetting function was adjusted to accept the transformed
lat/lon values as local variables.

Reported-by: Kasra Keshavarz <[email protected]>
Signed-off-by: Kasra Keshavarz <[email protected]>

* bumping version to 0.1.4

* removing the duplicate line for specifying longitude limits variable

* Correcting extent extraction from LandSat GeoTIFFs

Since converting the extents of input Shapefiles to the Landsat's
projection value resulted in spatially accurate GeoTIFFs, another
solution was implemented to: 1) reproject the input ESRI Shapefile into
the projection of the Landsat rasters and 2) extract the extents from
the reprojected ESRI Shapefile. This results in accurate spatial subset
of the Landsat landcover values.

Furthermore, the `extract_extent_shapefile()` function has changed in a
way that could be provided with the source projection where the extents
are desired. If not provided, the source projection of the ESRI
Shapefile input data is considered to extract the extents.

Signed-off-by: Kasra Keshavarz <[email protected]>
Reported-by: Kasra Keshavarz <[email protected]>

---------

Signed-off-by: Kasra Keshavarz <[email protected]>

Author: kasra-keshavarz

VERSION

@@ -1 +1 @@
-0.1.3
+0.1.4

landsat/landsat.sh

@@ -165,7 +165,6 @@ sort_comma_delimited () { IFS=',' read -ra arr <<< "$*"; echo ${arr[*]} | tr " "
 # log date format
 logDate () { echo "($(date +"%Y-%m-%d %H:%M:%S")) "; }
 
-
 #######################################
 # subset GeoTIFFs
 #
@@ -215,7 +214,6 @@ subset_geotiff () {
 		 > /dev/null;
 }
 
-
 #######################################
 # Extract ESRI Shapefile extents 
 #
@@ -226,8 +224,10 @@ subset_geotiff () {
 #	     lat/lon system
 #
 # Arguments:
-#   shapefilePath: Unix-style path to
-#                  an ESRI Shapefile
+#   shapefilePath: path to the ESRI
+#		   Shapefile
+#   destProj4: destination projection,
+#	       (optional)
 #
 # Outputs:
 #   one mosaiced (merged) GeoTIFF under
@@ -242,26 +242,102 @@ extract_shapefile_extents () {
 
   # reading arguments
   local shapefilePath=$1
+  local destProj4=$2
 
-  # extract the shapefile extent
-  IFS=' ' read -ra shapefileExtents <<< "$(ogrinfo -so -al "$shapefilePath" | sed 's/[),(]//g' | grep Extent)"
+  # extract PROJ.4 string for $shapefilePath
+  sourceProj4=$(ogrinfo -al -so $shapefilePath | grep -e "PROJ.4" 2>/dev/null)
+
+  # if $sourceProj4 is missing, assign EPSG:4326 as default value and warn
+  if [[ -z $sourceProj4 ]]; then
+    sourceProj4="EPSG:4326"
+    echo "$(logDate)$(basename $0): WARNING! Assuming EPSG:4326 for the" \
+    		"input ESRI Shapefile to extract the extents"
+  fi
+
+  # if $destProj4 provided, reproject and extract extent in the new
+  # projection
+  if [[ -n $destProj4 && "$destProj4" != "$sourceProj4" ]]; then
+    # temporary shapefile's path
+    tempShapefile="${cache}/temp_reprojected.shp"
+
+    # reproject ESRI shapefile to $destProj4
+    ogr2ogr -f "ESRI Shapefile" ${tempShapefile} ${shapefilePath} -s_srs \
+      "$sourceProj4" -t_srs "$destProj4"
 
-  # transform the extents in case they are not in EPSG:4326
-  IFS=':' read -ra sourceProj4 <<< "$(gdalsrsinfo $shapefilePath | grep -e "PROJ.4")" # source Proj4 value
-  if [[ -n $sourceProj4 ]]; then
-    :
-  else
-    echo "$(logDate)$(basename $0): WARNING! Assuming WSG84 CRS for the input ESRI Shapefile"
-    sourceProj4=("PROJ.4" " +proj=longlat +datum=WGS84 +no_defs") # made an array for compatibility with the following statements
+    # assign the path of the projected file as the $shapefilePath
+    shapefilePath="${tempShapefile}"
   fi
 
+  # extract the shapefile extent
+  IFS=' ' read -ra shapefileExtents <<< "$(ogrinfo -so -al "$shapefilePath" | sed 's/[),(]//g' | grep Extent)"
+  
   # transform limits and assigning to relevant variables
-  IFS=' ' read -ra leftBottomLims <<< $(echo "${shapefileExtents[@]:1:2}" | gdaltransform -s_srs "${sourceProj4[1]}" -t_srs EPSG:4326 -output_xy)
-  IFS=' ' read -ra rightTopLims <<< $(echo "${shapefileExtents[@]:4:5}" | gdaltransform -s_srs "${sourceProj4[1]}" -t_srs EPSG:4326 -output_xy)
+  IFS=' ' read -ra lowerLeftLims <<< $(echo "${shapefileExtents[@]:1:2}")
+  IFS=' ' read -ra upperRightLims <<< $(echo "${shapefileExtents[@]:4:5}")
 
   # define $latLims and $lonLims from $shapefileExtents
-  lonLims="${leftBottomLims[0]},${rightTopLims[0]}"
-  latLims="${leftBottomLims[1]},${rightTopLims[1]}"
+  lonLims="${lowerLeftLims[0]},${upperRightLims[0]}"
+  latLims="${lowerLeftLims[1]},${upperRightLims[1]}"
+}
+
+#######################################
+# Transform projection based on source
+#     Proj4 string
+#
+# Globals:
+#   None
+#
+# Arguments:
+#   sourceProj4: string describing
+#                source projection
+#   coords: comma-separated coordinate
+#	    values
+#   coordsDelim: delimited in the 
+#    		 $coords variable
+#   transformDelim: delimtied in the
+# 		    transformed values
+#   destEPSG: EPSG value of the
+#	      destination projection
+#	      (default 'EPSG:4326')
+#
+# Outputs:
+#   comma-delimited $coords in the
+#   $destEPSG format
+#######################################
+transform_coords () {
+  # local variables
+  local sourceProj4="$1"
+  local coords="$2"
+  local coordsDelim="$3"
+  local transformDelim="$4"
+  local destEPSG="$5"
+  # local variables assigned in the function
+  local coordsBlankDel
+  local coordsTrans
+
+  # if $destEPSG not provided, use EPSG:4326 by default
+  if [[ -z $destEPSG ]]; then
+    destEPSG='EPSG:4326'
+  fi
+
+  # if $coordsDelim not provided, use comma ',' by default
+  if [[ -z $coordsDelim ]]; then
+    coordsDelim=','
+  fi
+
+  # substituting comma with a blank space
+  coordsBlankDel=$(echo "$coords" | tr "${coordsDelim}" ' ')
+
+  # transforming coords
+  coordsTrans=$(echo "$coordsBlankDel" | gdaltransform -s_srs "${sourceProj4}" -t_srs "${destEPSG}" -output_xy)
+
+  # subtitute blank space with $transformDelim value
+  if [[ -n $transformDelim ]]; then
+    coordsTrans=$(echo "$coordsTrans" | tr ' ' $transformDelim)
+  fi
+  
+  # echo-ing $coordsTrans variable
+  echo "${coordsTrans}"
 }
 
 
@@ -345,18 +421,24 @@ for tif in $cache/*.tif; do
   tiffs+=($(basename "${tif}"))
 done
 
+# extracting raster projection PROJ.4 string value
+tempTif="${cache}/${tiffs[0]}"
+rasterProj4="$(gdalsrsinfo "${tempTif}" | grep -e "PROJ.4" | cut -d ':' -f2)"
+
 # if shapefile is provided extract the extents from it
 if [[ -n $shapefile ]]; then
   # create latLims and lonLims variables specifying the limits of the ESRI Shapefile
-  extract_shapefile_extents "${shapefile}"
+  extract_shapefile_extents "${shapefile}" "${rasterProj4}"
 fi
 
 # subset and produce stats if needed
 if [[ "${printGeotiff,,}" == "true" ]]; then
+  # echo message 
   echo "$(logDate)$(basename $0): subsetting GeoTIFFs under $outputDir"
+  
   for tif in "${tiffs[@]}"; do
     # subset based on lat and lon values
-    subset_geotiff "${cache}/${tif}" "${outputDir}/${prefix}${tif}"
+    subset_geotiff "${cache}/${tif}" "${outputDir}/${prefix}${tif}" "$latLims" "$lonLims"
   done
 fi