update: generate cogs with multiple method options

- default: COG with overview
- no overview: COG without overviews
- remove artifacts: Resamples to 400% and back to remove edge-artifacts
- hillshade: create hillshade and convert to cog
- rgb: generate a cog for RGB images

scripts/generate_cog.sh

@@ -1,19 +1,96 @@
-generate_cog () {
-    local MASK=$(mktemp .cog.XXXXXXX.tif -p .)
-    local NORMALIZED=$(mktemp .cog.XXXXXXX.tif -p .)
-    local RGBA=$(mktemp .cog.XXXXXXX.tif -p .)
-
-    gdal_translate -co NUM_THREADS=ALL_CPUS -scale 1 4 255 255 $1 $MASK
-    gdal_translate -co NUM_THREADS=ALL_CPUS -scale 1 4 0 255 $1 $NORMALIZED
-    gdal_merge.py -separate -o $RGBA -of GTiff -co NUM_THREADS=ALL_CPUS $NORMALIZED $NORMALIZED $NORMALIZED $MASK
-    gdal_translate $RGBA $1.cog -of COG -co NUM_THREADS=ALL_CPUS -co TARGET_SRS=EPSG:3857 -co ADD_ALPHA=NO -co COMPRESS=LZW -co LEVEL=9
-    rm $MASK $NORMALIZED $RGBA
+# Converts a raster to COG using a specific method
+# Default: Creates a COG with overviews
+# No overview: Creates a COG without overviews 
+# Remove artifacts: Creates a COG by resampling the raster to 400% and then back to the original size. 
+# This method can be used to remove edge-artifacts from the raster. Compute-intensive.
+# Note that resampling can change raster values and pixel sizes
+# Arguments:
+#   $1: input raster file
+#   $2: conversion method ("default", "no_overview", or "remove_artifacts")
+# Usage:
+#   to_cog raster.tif default
+#   to_cog raster.tif no_overview
+#   to_cog raster.tif remove_artifacts
+to_cog () {
+  local input_file="$1"
+  local method="$2"
+
+  set -o xtrace
+
+  case "$method" in
+    ("default")
+      gdal_translate "$input_file" "$input_file.cog" -co NUM_THREADS=ALL_CPUS -co TILING_SCHEME=GoogleMapsCompatible -of COG
+      ;;
+    ("no_overview")
+      gdal_translate "$input_file" "$input_file.cog" -co NUM_THREADS=ALL_CPUS -co TILING_SCHEME=GoogleMapsCompatible -co OVERVIEWS=NONE -of COG
+      ;;
+    ("remove_artifacts")
+      gdal_translate "$input_file" "$input_file.up" -co NUM_THREADS=ALL_CPUS -outsize 400% 400% -of GTiff && \
+      gdal_translate "$input_file.up" "$input_file.cog" -co NUM_THREADS=ALL_CPUS -co TILING_SCHEME=GoogleMapsCompatible -co OVERVIEWS=IGNORE_EXISTING -co RESAMPLING=average -of COG
+      rm "$input_file.up"
+      ;;
+    (*)
+      echo "Invalid method. Please use 'default', 'no_overview', or 'remove_artifacts'."
+      return 1
+      ;;
+  esac
+
+  set +o xtrace
 }
 
-generate_color_cog () {
-    local RGBA=$(mktemp .cog.XXXXXXX.tif -p .)
+#!/bin/bash
+# generate_hillshade_cog
+# Gonverts a DEM/DTM to a hillshade
+# Compresses to JPEG and converts to COG
+# Arguments:
+#   $1: input raster file with elevation data
+# Usage:
+#   generate_hillshade_cog raster.tif 25833
+generate_hillshade_cog() {
+    local filename="${1%.*}"
+    local HILLSHADE_TMP=$(mktemp .hillshade.XXXXXX.tif -p .)  
 
-    gdaldem color-relief $1 $2 $RGBA -alpha
-    gdal_translate $RGBA $1.cog -of COG -co TARGET_SRS=EPSG:3857 -co ADD_ALPHA=NO -co COMPRESS=LZW -co LEVEL=9
-    rm $RGBA
+    gdaldem hillshade $1 $HILLSHADE_TMP
+    gdal_translate $HILLSHADE_TMP $filename.hillshade.cog -co NUM_THREADS=ALL_CPUS -co TILING_SCHEME=GoogleMapsCompatible -of COG
+    rm $HILLSHADE_TMP
 }
+
+# generate_rgb_cog  
+# resample ortofoto to $variable
+# Compresses to DEFLATE and converts to COG
+# Arguments:
+#   $1: input raster file with RGB data
+#   $2: resample value (optional)
+# Usage:
+#   generate_rgb_cog raster.tif 25833 1
+generate_rgb_cog() {
+    local filename="${1%.*}"
+    local RGB_TMP=$(mktemp .rgb.XXXXXX.tif -p .)  
+
+    # Get file size in bytes
+    file_size_bytes=$(stat -c%s "$1")
+
+    # Convert file size to GB
+    file_size_gb=$(echo "$file_size_bytes / 1024 / 1024 / 1024" | bc)
+
+    # Check if file size is greater than 2 GB
+    if [ $file_size_gb -gt 2 ]
+    then
+        BLOCKSIZE=512
+        BIGTIFF=YES
+        echo "File size > 2 GB: Using BLOCKSIZE=512 and BIGTIFF=YES"
+    else
+        BLOCKSIZE=256
+        BIGTIFF=NO
+        echo "File size <= 2 GB: Using BLOCKSIZE=256 and BIGTIFF=NO"
+    fi
+
+    if [ -z "$2" ]; then
+        gdal_translate $1 $filename.cog -a_srs EPSG:$epsg -of COG -co BLOCKSIZE=$BLOCKSIZE -co OVERVIEW_RESAMPLING=BILINEAR -co COMPRESS=DEFLATE -co NUM_THREADS=ALL_CPUS -co BIGTIFF=$BIGTIFF
+    else
+        gdalwarp -tr $2 $2 -r bilinear $1 $RGB_TMP
+        echo "Resampling to $2"
+        gdal_translate $RGB_TMP $filename.cog -a_srs EPSG:$epsg -of COG -co BLOCKSIZE=$BLOCKSIZE -co OVERVIEW_RESAMPLING=BILINEAR -co COMPRESS=DEFLATE -co NUM_THREADS=ALL_CPUS -co BIGTIFF=$BIGTIFF
+    fi
+    rm $RGB_TMP
+}