From 69859c83af20c0df19d99fba3c475ce753e45acc Mon Sep 17 00:00:00 2001
From: Jodok Huber <jodokh@gmail.com>
Date: Thu, 8 May 2025 14:39:47 +0200
Subject: [PATCH] Do not write ModelPixelScale or ModelTiepoint when
 ModelTransformationTag is present (see specs:
 http://geotiff.maptools.org/spec/geotiff2.6.html)

---
 src/geotiffwriter.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/geotiffwriter.js b/src/geotiffwriter.js
index ea318477..c6bb79cb 100644
--- a/src/geotiffwriter.js
+++ b/src/geotiffwriter.js
@@ -355,7 +355,7 @@ export function writeGeotiff(data, metadata) {
     metadata.StripByteCounts = [numBands * height * width];
   }
 
-  if (!metadata.ModelPixelScale) {
+  if (!metadata.ModelPixelScale && !metadata.ModelTransformation) {
     // assumes raster takes up exactly the whole globe
     metadata.ModelPixelScale = [360 / width, 180 / height, 0];
   }
@@ -367,7 +367,9 @@ export function writeGeotiff(data, metadata) {
   // if didn't pass in projection information, assume the popular 4326 "geographic projection"
   if (!metadata.hasOwnProperty('GeographicTypeGeoKey') && !metadata.hasOwnProperty('ProjectedCSTypeGeoKey')) {
     metadata.GeographicTypeGeoKey = 4326;
-    metadata.ModelTiepoint = [0, 0, 0, -180, 90, 0]; // raster fits whole globe
+    if (!metadata.ModelTransformation) {
+      metadata.ModelTiepoint = [0, 0, 0, -180, 90, 0]; // raster fits whole globe
+    }
     metadata.GeogCitationGeoKey = 'WGS 84';
     metadata.GTModelTypeGeoKey = 2;
   }