From f15059d9869fb141a8b6e4c1428597761152a639 Mon Sep 17 00:00:00 2001
From: Elias Carvalho <eliascarvdev@gmail.com>
Date: Thu, 7 Nov 2024 16:41:15 -0300
Subject: [PATCH 1/3] Add utility functions to easily extract values from
 metadata

---
 src/GeoTIFF.jl   |  1 +
 src/userutils.jl | 57 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)
 create mode 100644 src/userutils.jl

diff --git a/src/GeoTIFF.jl b/src/GeoTIFF.jl
index 813b97e..756eac9 100644
--- a/src/GeoTIFF.jl
+++ b/src/GeoTIFF.jl
@@ -13,6 +13,7 @@ import TiffImages
 
 include("geokeys.jl")
 include("metadata.jl")
+include("userutils.jl")
 include("image.jl")
 include("load.jl")
 include("save.jl")
diff --git a/src/userutils.jl b/src/userutils.jl
new file mode 100644
index 0000000..68f8b99
--- /dev/null
+++ b/src/userutils.jl
@@ -0,0 +1,57 @@
+# -----------------------------------------------------------------
+# Licensed under the MIT License. See LICENSE in the project root.
+# -----------------------------------------------------------------
+
+function geokey(metadata::Metadata, id::GeoKeyID)
+  geokeys = metadata.geokeydirectory.geokeys
+  i = findfirst(geokey -> geokey.id == id, geokeys)
+  isnothing(i) ? nothing : geokeys[i]
+end
+
+function geokeyvalue(metadata::Metadata, id::GeoKeyID)
+  geokey = geokey(metadata, id)
+  isnothing(geokey) ? nothing : geokey.value
+end
+
+rastertype(metadata::Metadata) = geokeyvalue(metadata, GTRasterTypeGeoKey)
+
+modeltype(metadata::Metadata) = geokeyvalue(metadata, GTModelTypeGeoKey)
+
+function epsgcode(metadata::Metadata)
+  mt = modeltype(metadata)
+  isnothing(mt) && return nothing
+  if mt == Projected2D
+    geokeyvalue(metadata, ProjectedCRSGeoKey)
+  elseif mt == Geographic2D || mt == Geocentric3D
+    geokeyvalue(metadata, GeodeticCRSGeoKey)
+  else
+    # Undefined or UserDefined
+    nothing
+  end
+end
+
+function affineparams(metadata::Metadata)
+  pixelscale = metadata.modelpixelscale
+  tiepoint = metadata.modeltiepoint
+  transformation = metadata.modeltransformation
+  if !isnothing(pixelscale) && !isnothing(tiepoint)
+    sx = pixelscale.x
+    sy = pixelscale.y
+    sz = pixelscale.z
+    (; i, j, k, x, y, z) = tiepoint
+    tx = x - i / sx
+    ty = y + j / sy
+    tz = z - k / sz
+    A = [
+      sx 0 0
+      0 -sy 0
+      0 0 sz
+    ]
+    b = [tx, ty, tz]
+    A, b
+  elseif !isnothing(transformation)
+    transformation.A, transformation.b
+  else
+    nothing
+  end
+end

From 3b8ec9374b9460394da334265bc580fb5ba6b5c1 Mon Sep 17 00:00:00 2001
From: Elias Carvalho <eliascarvdev@gmail.com>
Date: Thu, 7 Nov 2024 17:12:21 -0300
Subject: [PATCH 2/3] Add 'affineparams2D'

---
 src/userutils.jl | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/userutils.jl b/src/userutils.jl
index 68f8b99..e98c6d4 100644
--- a/src/userutils.jl
+++ b/src/userutils.jl
@@ -30,7 +30,30 @@ function epsgcode(metadata::Metadata)
   end
 end
 
-function affineparams(metadata::Metadata)
+function affineparams2D(metadata::Metadata)
+  pixelscale = metadata.modelpixelscale
+  tiepoint = metadata.modeltiepoint
+  transformation = metadata.modeltransformation
+  if !isnothing(pixelscale) && !isnothing(tiepoint)
+    sx = pixelscale.x
+    sy = pixelscale.y
+    (; i, j, x, y) = tiepoint
+    tx = x - i / sx
+    ty = y + j / sy
+    A = [
+      sx 0
+      0 -sy
+    ]
+    b = [tx, ty]
+    A, b
+  elseif !isnothing(transformation)
+    transformation.A[1:2, 1:2], transformation.b[1:2]
+  else
+    nothing
+  end
+end
+
+function affineparams3D(metadata::Metadata)
   pixelscale = metadata.modelpixelscale
   tiepoint = metadata.modeltiepoint
   transformation = metadata.modeltransformation

From bb4643d646230a18433094260d1f5df63afe01f3 Mon Sep 17 00:00:00 2001
From: Elias Carvalho <eliascarvdev@gmail.com>
Date: Thu, 7 Nov 2024 17:18:50 -0300
Subject: [PATCH 3/3] Fix code

---
 src/metadata.jl  | 8 ++++----
 src/userutils.jl | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/metadata.jl b/src/metadata.jl
index 94dfb91..a52e23e 100644
--- a/src/metadata.jl
+++ b/src/metadata.jl
@@ -31,10 +31,10 @@ GeoKeyDirectory(; version=1, revision=1, minor=1, geokeys=GeoKey[]) =
 function GeoKeyDirectory(params::Vector{UInt16})
   nkeys = params[4]
   geokeys = map((1:nkeys) * 4) do i
-    id = GeoKeyID(geokey[1 + i])
-    tag = geokey[2 + i]
-    count = geokey[3 + i]
-    value = geokey[4 + i]
+    id = GeoKeyID(params[1 + i])
+    tag = params[2 + i]
+    count = params[3 + i]
+    value = params[4 + i]
     GeoKey(id, tag, count, value)
   end
 
diff --git a/src/userutils.jl b/src/userutils.jl
index e98c6d4..b4b6a31 100644
--- a/src/userutils.jl
+++ b/src/userutils.jl
@@ -9,8 +9,8 @@ function geokey(metadata::Metadata, id::GeoKeyID)
 end
 
 function geokeyvalue(metadata::Metadata, id::GeoKeyID)
-  geokey = geokey(metadata, id)
-  isnothing(geokey) ? nothing : geokey.value
+  gk = geokey(metadata, id)
+  isnothing(gk) ? nothing : gk.value
 end
 
 rastertype(metadata::Metadata) = geokeyvalue(metadata, GTRasterTypeGeoKey)