set gdal roles for well known tags

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - ConstantTile with NoData: support idempotent CellType conversions [#3553](https://github.com/locationtech/geotrellis/pull/3553)
 - GeoTiffReader Unknown tags skip fix [#3557](https://github.com/locationtech/geotrellis/pull/3557)
 - Fix implicitNotFound error and rename RGBAMethods implicit class [#3563](https://github.com/locationtech/geotrellis/pull/3563)
+- Set 'role' attribute in GDALMetadata tag written to tiff header, to match GDAL behaviour. [#3496](https://github.com/locationtech/geotrellis/issues/3496)
 
 ## [3.7.1] - 2024-01-08
 

raster/src/main/scala/geotrellis/raster/io/geotiff/Tags.scala

@@ -49,7 +49,10 @@ case class Tags(headTags: Map[String, String], bandTags: List[Map[String, String
     val bandTagsXml: Seq[scala.xml.Elem] =
       bandTags.zipWithIndex.flatMap { case (map, i) =>
         map.toSeq.map { case (key, value) =>
-          <Item name={key} sample={i.toString}>{value}</Item>
+          if (Tags.TAG_ROLES.contains(key.toLowerCase()))
+            <Item name={key} sample={i.toString} role={key.toLowerCase}>{value}</Item>
+          else
+            <Item name={key} sample={i.toString}>{value}</Item>
         }
       }
 
@@ -65,4 +68,13 @@ object Tags {
 
   final val AREA_OR_POINT = "AREA_OR_POINT"
   final val TIFFTAG_DATETIME = "TIFFTAG_DATETIME"
+  final val TIFFTAG_IMAGEDESCRIPTION = "TIFFTAG_IMAGEDESCRIPTION"
+  final val TAG_ROLES = Set(
+    "offset",
+    "scale",
+    "description",
+    "unittype",
+    "colorinterp"
+  )
+
 }

raster/src/test/scala/geotrellis/raster/io/geotiff/writer/GeoTiffWriterSpec.scala

@@ -26,11 +26,12 @@ import geotrellis.raster.testkit._
 import geotrellis.vector.Extent
 
 import java.io._
-
 import org.scalatest.{BeforeAndAfterAll, Inspectors}
 import org.scalatest.matchers.should.Matchers
 import org.scalatest.funspec.AnyFunSpec
 
+import scala.xml.{Text, XML}
+
 class GeoTiffWriterSpec extends AnyFunSpec with Matchers with BeforeAndAfterAll with RasterMatchers with TileBuilders with GeoTiffTestUtils {
 
   override def afterAll() = purge
@@ -113,15 +114,59 @@ class GeoTiffWriterSpec extends AnyFunSpec with Matchers with BeforeAndAfterAll
 
       val newTag1 = ("SOME_CUSTOM_TAG1" -> "1234567890123456789012345678901")
       val newTag2 = ("SOME_CUSTOM_TAG2" -> "12345678901234567890123456789012")
+      val newTag3 = ("OFFSET" -> "43")
+      val newTag4 = ("DESCRIPTION" -> "band description")
+      val newTag5 = ("SCALE" -> "0.1")
       val headTags = geoTiff.tags.headTags + newTag1 + newTag2
-      val bandTags = geoTiff.tags.bandTags.map(_ + newTag1 + newTag2)
+      val bandTags = geoTiff.tags.bandTags.map(_ + newTag1 + newTag2 + newTag3 + newTag4 + newTag5)
 
       val taggedTiff = geoTiff.copy(tags = Tags(headTags, bandTags))
 
       GeoTiffWriter.write(taggedTiff, path)
 
       addToPurge(path)
 
+      val tags = TiffTags.read(path)
+
+      val expectedXML = XML.loadString("""<GDALMetadata>
+        <Item name="SOME_CUSTOM_TAG2">12345678901234567890123456789012</Item>
+        <Item name="TAG_TYPE">HEAD</Item>
+        <Item name="SOME_CUSTOM_TAG1">1234567890123456789012345678901</Item>
+        <Item name="HEADTAG">1</Item>
+        <Item name="SOME_CUSTOM_TAG2" sample="0">12345678901234567890123456789012</Item>
+        <Item name="DESCRIPTION" sample="0" role="description">band description</Item>
+        <Item name="TAG_TYPE" sample="0">BAND1</Item>
+        <Item name="BANDTAG" sample="0">1</Item>
+        <Item name="OFFSET" sample="0" role="offset">43</Item>
+        <Item name="SOME_CUSTOM_TAG1" sample="0">1234567890123456789012345678901</Item>
+        <Item name="SCALE" sample="0" role="scale">0.1</Item>
+        <Item name="SOME_CUSTOM_TAG2" sample="1">12345678901234567890123456789012</Item>
+        <Item name="DESCRIPTION" sample="1" role="description">band description</Item>
+        <Item name="TAG_TYPE" sample="1">BAND2</Item>
+        <Item name="BANDTAG" sample="1">2</Item>
+        <Item name="OFFSET" sample="1" role="offset">43</Item>
+        <Item name="SOME_CUSTOM_TAG1" sample="1">1234567890123456789012345678901</Item>
+        <Item name="SCALE" sample="1" role="scale">0.1</Item>
+        <Item name="SOME_CUSTOM_TAG2" sample="2">12345678901234567890123456789012</Item>
+        <Item name="DESCRIPTION" sample="2" role="description">band description</Item>
+        <Item name="TAG_TYPE" sample="2">BAND3</Item>
+        <Item name="BANDTAG" sample="2">3</Item>
+        <Item name="OFFSET" sample="2" role="offset">43</Item>
+        <Item name="SOME_CUSTOM_TAG1" sample="2">1234567890123456789012345678901</Item>
+        <Item name="SCALE" sample="2" role="scale">0.1</Item>
+        <Item name="SOME_CUSTOM_TAG2" sample="3">12345678901234567890123456789012</Item>
+        <Item name="DESCRIPTION" sample="3" role="description">band description</Item>
+        <Item name="TAG_TYPE" sample="3">BAND4</Item>
+        <Item name="BANDTAG" sample="3">4</Item>
+        <Item name="OFFSET" sample="3" role="offset">43</Item>
+        <Item name="SOME_CUSTOM_TAG1" sample="3">1234567890123456789012345678901</Item>
+        <Item name="SCALE" sample="3" role="scale">0.1</Item>
+      </GDALMetadata>""")
+      val expectedItems = expectedXML.child.filter(_.isInstanceOf[scala.xml.Elem]).sortBy(_.attribute("name").get.text).sortBy(_.attribute("sample").getOrElse(Text("")).text)
+      val actualItems = XML.loadString(tags.geoTiffTags.metadata.get).child.filter(_.isInstanceOf[scala.xml.Elem]).sortBy(_.attribute("name").get.text).sortBy(_.attribute("sample").getOrElse(Text("")).text)
+
+      actualItems.zip(expectedItems).foreach(t=> t._1 should equal (t._2))
+
       val actual = MultibandGeoTiff(path).tags
       val expected = taggedTiff.tags