Fixes on Image returns

Changelog.md

@@ -1,5 +1,7 @@
 ## 0.0.34
-*INCOMPLETE*
++ Added `Image.channels` field for inspecting image channel count.
++ Fixed edge prediction output `Image` having incorrect `width` and `height`.
++ Updated to Function C 0.0.20.
 
 ## 0.0.33
 + Fixed edge prediction errors caused by request backpressure while the predictor is being loaded.

src/api/client.ts

@@ -3,7 +3,7 @@
 *   Copyright © 2024 NatML Inc. All Rights Reserved.
 */
 
-import { FunctionConfig } from "../function"
+import type { FunctionConfig } from "../function"
 
 export interface GraphPayload<T> {
     /**

src/services/prediction.ts

@@ -98,7 +98,7 @@ export class PredictionService {
     private fxnc: any;
     private readonly FXNC_DATA_ROOT = "/fxn";
     private readonly FXNC_CACHE_ROOT = `${this.FXNC_DATA_ROOT}/cache`;
-    private readonly FXNC_VERSION = "0.0.19";
+    private readonly FXNC_VERSION = "0.0.20";
     private readonly FXNC_LIB_URL_BASE = `https://cdn.fxn.ai/edgefxn/${this.FXNC_VERSION}`;
 
     public constructor (client: GraphClient, storage: StorageService) {
@@ -251,10 +251,10 @@ export class PredictionService {
             return { data, type, shape: value.shape };
         }
         // Image
-        if (isImage(value)) {
+        if (isImage(value)) { // INCOMPLETE // Remove `canvas` dependency
             const canvas = createCanvas(value.width, value.height);
             const ctx = canvas.getContext("2d");
-            ctx.putImageData(value as ImageData, 0, 0);
+            ctx.putImageData(value as unknown as ImageData, 0, 0);
             const data = canvas.toDataURL();
             return { data, type: "image" };
         }
@@ -718,8 +718,8 @@ export class PredictionService {
                 case FXNDtype.String:   return fxnc.UTF8ToString(pData);
                 case FXNDtype.List:     return JSON.parse(fxnc.UTF8ToString(pData));
                 case FXNDtype.Dict:     return JSON.parse(fxnc.UTF8ToString(pData));
-                case FXNDtype.Image:    return toImage(new Uint8Array(fxnc.HEAPU8.buffer, pData, elementCount), shape);
-                case FXNDtype.Binary:   return toArrayBuffer(new Uint8Array(fxnc.HEAPU8.buffer, pData, elementCount));
+                case FXNDtype.Image:    return { data: cloneTypedArray(new Uint8ClampedArray(fxnc.HEAPU8.buffer, pData, elementCount)), width: shape[1], height: shape[0], channels: shape[2] };
+                case FXNDtype.Binary:   return cloneTypedArray(new Uint8Array(fxnc.HEAPU8.buffer, pData, elementCount)).buffer;
                 default:                throw new Error(`Cannot convert prediction output to value because of unknown type: ${type}`);
             }
         } finally {
@@ -820,14 +820,6 @@ function toBooleanArrayOrBoolean (buffer: ArrayBuffer, shape: number[]): boolean
     return shape.length > 0 ? array : array[0];
 }
 
-function toImage (data: Uint8Array, shape: number[]): Image {
-    return { data: cloneTypedArray(data), width: shape[2], height: shape[1] };
-}
-
-function toArrayBuffer (data: Uint8Array): ArrayBuffer {
-    return cloneTypedArray(data).buffer;
-}
-
 function getTypedArrayDtype (data: TypedArray | ArrayBuffer): FXNDtype {
     if (data instanceof BoolArray)          return FXNDtype.Bool;
     if (data instanceof Float32Array)       return FXNDtype.Float32;

src/services/value.ts

@@ -44,7 +44,7 @@ export function isTensor (value: any): value is Tensor {
  * @param value Input value.
  * @returns Whether the input value is an image.
  */
-export function isImage (value: any): value is Image {
+export function isImage (value: any): value is Image { // CHECK // Channel count
     return value != null &&
         (value.data instanceof Uint8Array || value.data instanceof Uint8ClampedArray) &&
         Number.isInteger(value.width) &&

src/types/value.ts

@@ -23,7 +23,6 @@ export type TypedArray =
 
 /**
  * Image.
- * This is strucurally equal to `ImageData`.
  * @see https://developer.mozilla.org/en-US/docs/Web/API/ImageData
  */
 export interface Image {
@@ -40,6 +39,10 @@ export interface Image {
      * Image height.
      */
     height: number;
+    /**
+     * Image channels.
+     */
+    channels: number;
 }
 
 /**