From ffd9ec32730580e266ffae365a10ac3e524dd6cf Mon Sep 17 00:00:00 2001
From: Ibrahim <93064150+IbrahimCSAE@users.noreply.github.com>
Date: Mon, 20 Oct 2025 13:07:39 -0400
Subject: [PATCH] fix(rendering): Fix palette color LUT conversion causing
 black images (#5509)

The palette color LUT was incorrectly handling 16 bit entries, and didn't work for both array buffers and typed arrays.
---
 .../fetchPaletteColorLookupTableData.js       | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/platform/core/src/utils/metadataProvider/fetchPaletteColorLookupTableData.js b/platform/core/src/utils/metadataProvider/fetchPaletteColorLookupTableData.js
index a3d5a7aea..8dd053cbd 100644
--- a/platform/core/src/utils/metadataProvider/fetchPaletteColorLookupTableData.js
+++ b/platform/core/src/utils/metadataProvider/fetchPaletteColorLookupTableData.js
@@ -30,18 +30,15 @@ function _getPaletteColor(paletteColorLookupTableData, lutDescriptor) {
   }
 
   const arrayBufferToPaletteColorLUT = arraybuffer => {
+    // Handle both ArrayBuffer and TypedArray inputs
+    const buffer = arraybuffer.buffer || arraybuffer;
+    const data = bits === 16 ? new Uint16Array(buffer) : new Uint8Array(buffer);
     const lut = [];
 
-    if (bits === 16) {
-      let j = 0;
-      for (let i = 0; i < numLutEntries; i++) {
-        lut[i] = (arraybuffer[j++] + arraybuffer[j++]) << 8;
-      }
-    } else {
-      for (let i = 0; i < numLutEntries; i++) {
-        lut[i] = arraybuffer[i];
-      }
+    for (let i = 0; i < numLutEntries; i++) {
+      lut[i] = data[i];
     }
+
     return lut;
   };
 
@@ -51,10 +48,10 @@ function _getPaletteColor(paletteColorLookupTableData, lutDescriptor) {
 
   if (paletteColorLookupTableData.InlineBinary) {
     try {
-      const arraybuffer = Uint8Array.from(atob(paletteColorLookupTableData.InlineBinary), c =>
+      const uint8Array = Uint8Array.from(atob(paletteColorLookupTableData.InlineBinary), c =>
         c.charCodeAt(0)
       );
-      return (paletteColorLookupTableData.palette = arrayBufferToPaletteColorLUT(arraybuffer));
+      return (paletteColorLookupTableData.palette = arrayBufferToPaletteColorLUT(uint8Array));
     } catch (e) {
       console.log("Couldn't decode", paletteColorLookupTableData.InlineBinary, e);
       return undefined;