feat: add 16 bit data type scale under a decode flag (#501)

* feat: add 16 bit data type scale under a decode flag

* fix linter

Author: sedghi

src/imageLoader/createImage.js

@@ -142,7 +142,7 @@ function createImage(imageId, pixelData, transferSyntax, options = {}) {
   );
 
   const { decodeConfig } = getOptions();
-  const { convertFloatPixelDataToInt } = decodeConfig;
+  const { convertFloatPixelDataToInt, use16BitDataType } = decodeConfig;
 
   return new Promise((resolve, reject) => {
     // eslint-disable-next-line complexity
@@ -173,9 +173,12 @@ function createImage(imageId, pixelData, transferSyntax, options = {}) {
           case 'Uint8Array':
             TypedArrayConstructor = Uint8Array;
             break;
-          case 'Uint16Array':
+          case use16BitDataType && 'Uint16Array':
             TypedArrayConstructor = Uint16Array;
             break;
+          case use16BitDataType && 'Int16Array':
+            TypedArrayConstructor = Int16Array;
+            break;
           case 'Float32Array':
             TypedArrayConstructor = Float32Array;
             break;

src/imageLoader/internal/options.js

@@ -14,6 +14,7 @@ let options = {
   strict: false,
   decodeConfig: {
     convertFloatPixelDataToInt: true,
+    use16BitDataType: false,
   },
 };
 

src/shared/decodeImageFrame.js

@@ -140,14 +140,18 @@ function decodeImageFrame(
 
   decodePromise
     .then((imageFrame) => {
-      callbackFn(postProcessDecodedPixels(imageFrame, options, start));
+      callbackFn(
+        postProcessDecodedPixels(imageFrame, options, start, decodeConfig)
+      );
     })
     .catch((err) => {
       throw err;
     });
 }
 
-function postProcessDecodedPixels(imageFrame, options, start) {
+function postProcessDecodedPixels(imageFrame, options, start, decodeConfig) {
+  const { use16BitDataType } = decodeConfig;
+
   const shouldShift =
     imageFrame.pixelRepresentation !== undefined &&
     imageFrame.pixelRepresentation === 1;
@@ -191,9 +195,12 @@ function postProcessDecodedPixels(imageFrame, options, start) {
       case 'Uint8Array':
         TypedArrayConstructor = Uint8Array;
         break;
-      case 'Uint16Array':
+      case use16BitDataType && 'Uint16Array':
         TypedArrayConstructor = Uint16Array;
         break;
+      case use16BitDataType && 'Int16Array':
+        TypedArrayConstructor = Int16Array;
+        break;
       case 'Float32Array':
         TypedArrayConstructor = Float32Array;
         break;