image processing fixes

.eslintrc.json

@@ -38,6 +38,7 @@
     "@typescript-eslint/no-shadow": "error",
     "@typescript-eslint/no-var-requires": "off",
     "@typescript-eslint/triple-slash-reference": "off",
+    "@typescript-eslint/no-inferrable-types": "off",
     "camelcase": "off",
     "dot-notation": "off",
     "func-names": "off",

demo/index.js

@@ -31,6 +31,15 @@ import jsonView from './helpers/jsonview.js';
 let human;
 
 let userConfig = {
+  cacheSensitivity: 0,
+  hand: { enabled: true },
+  body: { enabled: false },
+  face: { enabled: false },
+  /*
+  hand: { enabled: false, maxDetected: 1, skipFrames: 0 },
+  body: { enabled: false },
+  face: { enabled: false },
+  */
   /*
   warmup: 'none',
   backend: 'humangl',
@@ -259,7 +268,7 @@ async function drawResults(input) {
     }
     // result.canvas = seg.alpha;
   } else if (!result.canvas || ui.buffered) { // refresh with input if using buffered output or if missing canvas
-    const image = await human.image(input);
+    const image = await human.image(input, false);
     result.canvas = image.canvas;
     human.tf.dispose(image.tensor);
   }
@@ -302,17 +311,17 @@ async function drawResults(input) {
 
   // update log
   const engine = human.tf.engine();
-  const gpu = engine.backendInstance ? `gpu: ${(engine.backendInstance.numBytesInGPU ? engine.backendInstance.numBytesInGPU : 0).toLocaleString()} bytes` : '';
-  const memory = `system: ${engine.state.numBytes.toLocaleString()} bytes ${gpu} | tensors: ${engine.state.numTensors.toLocaleString()}`;
   const processing = result.canvas ? `processing: ${result.canvas.width} x ${result.canvas.height}` : '';
   const avgDetect = ui.detectFPS.length > 0 ? Math.trunc(10 * ui.detectFPS.reduce((a, b) => a + b, 0) / ui.detectFPS.length) / 10 : 0;
   const avgDraw = ui.drawFPS.length > 0 ? Math.trunc(10 * ui.drawFPS.reduce((a, b) => a + b, 0) / ui.drawFPS.length) / 10 : 0;
   const warning = (ui.detectFPS.length > 5) && (avgDetect < 2) ? '<font color="lightcoral">warning: your performance is low: try switching to higher performance backend, lowering resolution or disabling some models</font>' : '';
   const fps = avgDetect > 0 ? `FPS process:${avgDetect} refresh:${avgDraw}` : '';
-  const backend = engine.state.numTensors > 0 ? `${human.tf.getBackend()} | ${memory}` : `${result.backend} | tensors: ${result.tensors} in worker`;
+  const backend = result.backend || human.tf.getBackend();
+  const gpu = engine.backendInstance ? `gpu: ${(engine.backendInstance.numBytesInGPU ? engine.backendInstance.numBytesInGPU : 0).toLocaleString()} bytes` : '';
+  const memory = result.tensors || `system: ${engine.state.numBytes.toLocaleString()} bytes ${gpu} | tensors: ${engine.state.numTensors.toLocaleString()}`;
   document.getElementById('log').innerHTML = `
     video: ${ui.camera.name} | facing: ${ui.camera.facing} | screen: ${window.innerWidth} x ${window.innerHeight} camera: ${ui.camera.width} x ${ui.camera.height} ${processing}<br>
-    backend: ${backend}<br>
+    backend: ${backend} | ${memory}<br>
     performance: ${str(interpolated.performance)}ms ${fps}<br>
     ${warning}<br>
   `;

src/body/blazepose.ts

@@ -142,6 +142,11 @@ async function detectParts(input: Tensor, config: Config, outputSize: [number, n
 }
 
 export async function predict(input: Tensor, config: Config): Promise<BodyResult[]> {
+  /** blazepose caching
+   * not fully implemented
+   * 1. if skipFrame returned cached
+   * 2. run detection based on squared full frame
+   */
   const outputSize: [number, number] = [input.shape[2] || 0, input.shape[1] || 0];
   if ((skipped < (config.body.skipFrames || 0)) && config.skipFrame) {
     skipped++;

src/body/efficientpose.ts

@@ -7,17 +7,19 @@
 import { log, join } from '../util/util';
 import * as tf from '../../dist/tfjs.esm.js';
 import * as coords from './efficientposecoords';
-import type { BodyKeypoint, BodyResult, Box, Point } from '../result';
+import type { BodyResult, Point } from '../result';
 import type { GraphModel, Tensor } from '../tfjs/types';
 import type { Config } from '../config';
 import { env } from '../util/env';
 
 let model: GraphModel | null;
 
-const keypoints: Array<BodyKeypoint> = [];
-let box: Box = [0, 0, 0, 0];
-let boxRaw: Box = [0, 0, 0, 0];
-let score = 0;
+const cache: BodyResult = { id: 0, keypoints: [], box: [0, 0, 0, 0], boxRaw: [0, 0, 0, 0], score: 0, annotations: {} };
+
+// const keypoints: Array<BodyKeypoint> = [];
+// let box: Box = [0, 0, 0, 0];
+// let boxRaw: Box = [0, 0, 0, 0];
+// let score = 0;
 let skipped = Number.MAX_SAFE_INTEGER;
 
 export async function load(config: Config): Promise<GraphModel> {
@@ -48,9 +50,14 @@ function max2d(inputs, minScore) {
 }
 
 export async function predict(image: Tensor, config: Config): Promise<BodyResult[]> {
-  if ((skipped < (config.body?.skipFrames || 0)) && config.skipFrame && Object.keys(keypoints).length > 0) {
+  /** blazepose caching
+   * not fully implemented
+   * 1. if skipFrame returned cached
+   * 2. run detection based on squared full frame
+   */
+  if ((skipped < (config.body?.skipFrames || 0)) && config.skipFrame && Object.keys(cache.keypoints).length > 0) {
     skipped++;
-    return [{ id: 0, score, box, boxRaw, keypoints, annotations: {} }];
+    return [cache];
   }
   skipped = 0;
   return new Promise(async (resolve) => {
@@ -67,7 +74,7 @@ export async function predict(image: Tensor, config: Config): Promise<BodyResult
     tf.dispose(tensor);
 
     if (resT) {
-      keypoints.length = 0;
+      cache.keypoints.length = 0;
       const squeeze = resT.squeeze();
       tf.dispose(resT);
       // body parts are basically just a stack of 2d tensors
@@ -77,8 +84,8 @@ export async function predict(image: Tensor, config: Config): Promise<BodyResult
       for (let id = 0; id < stack.length; id++) {
         // actual processing to get coordinates and score
         const [x, y, partScore] = max2d(stack[id], config.body.minConfidence);
-        if (score > (config.body?.minConfidence || 0)) {
-          keypoints.push({
+        if (partScore > (config.body?.minConfidence || 0)) {
+          cache.keypoints.push({
             score: Math.round(100 * partScore) / 100,
             part: coords.kpt[id],
             positionRaw: [ // normalized to 0..1
@@ -94,33 +101,32 @@ export async function predict(image: Tensor, config: Config): Promise<BodyResult
       }
       stack.forEach((s) => tf.dispose(s));
     }
-    score = keypoints.reduce((prev, curr) => (curr.score > prev ? curr.score : prev), 0);
-    const x = keypoints.map((a) => a.position[0]);
-    const y = keypoints.map((a) => a.position[1]);
-    box = [
+    cache.score = cache.keypoints.reduce((prev, curr) => (curr.score > prev ? curr.score : prev), 0);
+    const x = cache.keypoints.map((a) => a.position[0]);
+    const y = cache.keypoints.map((a) => a.position[1]);
+    cache.box = [
       Math.min(...x),
       Math.min(...y),
       Math.max(...x) - Math.min(...x),
       Math.max(...y) - Math.min(...y),
     ];
-    const xRaw = keypoints.map((a) => a.positionRaw[0]);
-    const yRaw = keypoints.map((a) => a.positionRaw[1]);
-    boxRaw = [
+    const xRaw = cache.keypoints.map((a) => a.positionRaw[0]);
+    const yRaw = cache.keypoints.map((a) => a.positionRaw[1]);
+    cache.boxRaw = [
       Math.min(...xRaw),
       Math.min(...yRaw),
       Math.max(...xRaw) - Math.min(...xRaw),
       Math.max(...yRaw) - Math.min(...yRaw),
     ];
-    const annotations: Record<string, Point[][]> = {};
     for (const [name, indexes] of Object.entries(coords.connected)) {
       const pt: Array<Point[]> = [];
       for (let i = 0; i < indexes.length - 1; i++) {
-        const pt0 = keypoints.find((kpt) => kpt.part === indexes[i]);
-        const pt1 = keypoints.find((kpt) => kpt.part === indexes[i + 1]);
+        const pt0 = cache.keypoints.find((kpt) => kpt.part === indexes[i]);
+        const pt1 = cache.keypoints.find((kpt) => kpt.part === indexes[i + 1]);
         if (pt0 && pt1 && pt0.score > (config.body.minConfidence || 0) && pt1.score > (config.body.minConfidence || 0)) pt.push([pt0.position, pt1.position]);
       }
-      annotations[name] = pt;
+      cache.annotations[name] = pt;
     }
-    resolve([{ id: 0, score, box, boxRaw, keypoints, annotations }]);
+    resolve([cache]);
   });
 }

src/body/movenet.ts

@@ -42,6 +42,20 @@ export async function load(config: Config): Promise<GraphModel> {
   return model;
 }
 
+function fixSides() { // model sometimes mixes up left vs right keypoints so we fix them
+  for (const pair of coords.pairs) {
+    let left = keypoints.find((kp) => kp.part === pair[0]);
+    let right = keypoints.find((kp) => kp.part === pair[1]);
+    if (left && right) {
+      if (left.position[0] > right.position[0]) {
+        const tmp = left;
+        left = right;
+        right = tmp;
+      }
+    }
+  }
+}
+
 async function parseSinglePose(res, config, image, inputBox) {
   const kpt = res[0][0];
   keypoints.length = 0;
@@ -64,6 +78,7 @@ async function parseSinglePose(res, config, image, inputBox) {
       });
     }
   }
+  fixSides();
   score = keypoints.reduce((prev, curr) => (curr.score > prev ? curr.score : prev), 0);
   const bodies: Array<BodyResult> = [];
   const newBox = box.calc(keypoints.map((pt) => pt.position), [image.shape[2], image.shape[1]]);
@@ -103,6 +118,7 @@ async function parseMultiPose(res, config, image, inputBox) {
           });
         }
       }
+      fixSides();
       const newBox = box.calc(keypoints.map((pt) => pt.position), [image.shape[2], image.shape[1]]);
       // movenet-multipose has built-in box details
       // const boxRaw: Box = [kpt[51 + 1], kpt[51 + 0], kpt[51 + 3] - kpt[51 + 1], kpt[51 + 2] - kpt[51 + 0]];
@@ -126,6 +142,13 @@ async function parseMultiPose(res, config, image, inputBox) {
 }
 
 export async function predict(input: Tensor, config: Config): Promise<BodyResult[]> {
+  /** movenet caching
+   * 1. if skipFrame returned cached
+   * 2. if enough cached boxes run using cached boxes
+   * 3. if not enough detected bodies rerun using full frame
+   * 4. regenerate cached boxes based on current keypoints
+   */
+
   if (!model || !model?.inputs[0].shape) return []; // something is wrong with the model
   if (!config.skipFrame) cache.boxes.length = 0; // allowed to use cache or not
   skipped++; // increment skip frames
@@ -153,7 +176,6 @@ export async function predict(input: Tensor, config: Config): Promise<BodyResult
       t.res = await model?.predict(t.cast) as Tensor;
       const res = await t.res.array();
       cache.bodies = (t.res.shape[2] === 17) ? await parseSinglePose(res, config, input, [0, 0, 1, 1]) : await parseMultiPose(res, config, input, [0, 0, 1, 1]);
-      // cache.bodies = cache.bodies.map((body) => ({ ...body, box: box.scale(body.box, 0.5) }));
       Object.keys(t).forEach((tensor) => tf.dispose(t[tensor]));
     }
     cache.boxes.length = 0; // reset cache

src/body/movenetcoords.ts

@@ -18,6 +18,17 @@ export const kpt: Array<string> = [
   'rightAnkle',
 ];
 
+export const pairs: Array<string[]> = [
+  ['leftEye', 'rightEye'],
+  ['leftEar', 'rightEar'],
+  ['leftShoulder', 'rightShoulder'],
+  ['leftElbow', 'rightElbow'],
+  ['leftWrist', 'rightWrist'],
+  ['leftHip', 'rightHip'],
+  ['leftKnee', 'rightKnee'],
+  ['leftAnkle', 'rightAnkle'],
+];
+
 export const connected: Record<string, string[]> = {
   leftLeg: ['leftHip', 'leftKnee', 'leftAnkle'],
   rightLeg: ['rightHip', 'rightKnee', 'rightAnkle'],

src/body/posenet.ts

@@ -156,6 +156,9 @@ export function decode(offsets, scores, displacementsFwd, displacementsBwd, maxD
 }
 
 export async function predict(input: Tensor, config: Config): Promise<BodyResult[]> {
+  /** posenet is mostly obsolete
+   * caching is not implemented
+   */
   const res = tf.tidy(() => {
     if (!model.inputs[0].shape) return [];
     const resized = tf.image.resizeBilinear(input, [model.inputs[0].shape[2], model.inputs[0].shape[1]]);

src/gesture/gesture.ts

@@ -47,14 +47,14 @@ export const body = (res): GestureResult[] => {
     const leftWrist = res[i].keypoints.find((a) => (a.part === 'leftWrist'));
     const rightWrist = res[i].keypoints.find((a) => (a.part === 'rightWrist'));
     const nose = res[i].keypoints.find((a) => (a.part === 'nose'));
-    if (nose && leftWrist && rightWrist && (leftWrist.position.y < nose.position.y) && (rightWrist.position.y < nose.position.y)) gestures.push({ body: i, gesture: 'i give up' });
-    else if (nose && leftWrist && (leftWrist.position.y < nose.position.y)) gestures.push({ body: i, gesture: 'raise left hand' });
-    else if (nose && rightWrist && (rightWrist.position.y < nose.position.y)) gestures.push({ body: i, gesture: 'raise right hand' });
+    if (nose && leftWrist && rightWrist && (leftWrist.position[1] < nose.position[1]) && (rightWrist.position[1] < nose.position[1])) gestures.push({ body: i, gesture: 'i give up' });
+    else if (nose && leftWrist && (leftWrist.position[1] < nose.position[1])) gestures.push({ body: i, gesture: 'raise left hand' });
+    else if (nose && rightWrist && (rightWrist.position[1] < nose.position[1])) gestures.push({ body: i, gesture: 'raise right hand' });
 
     // leaning
     const leftShoulder = res[i].keypoints.find((a) => (a.part === 'leftShoulder'));
     const rightShoulder = res[i].keypoints.find((a) => (a.part === 'rightShoulder'));
-    if (leftShoulder && rightShoulder) gestures.push({ body: i, gesture: `leaning ${(leftShoulder.position.y > rightShoulder.position.y) ? 'left' : 'right'}` });
+    if (leftShoulder && rightShoulder) gestures.push({ body: i, gesture: `leaning ${(leftShoulder.position[1] > rightShoulder.position[1]) ? 'left' : 'right'}` });
   }
   return gestures;
 };

src/hand/handtrack.ts

@@ -23,7 +23,9 @@ const inputSize = [[0, 0], [0, 0]];
 
 const classes = ['hand', 'fist', 'pinch', 'point', 'face', 'tip', 'pinchtip'];
 
-const boxExpandFact = 1.6; // increase to 160%
+const boxExpandFact = 1.6;
+const maxDetectorResolution = 512;
+const detectorExpandFact = 1.2;
 
 let skipped = 0;
 let outputSize: [number, number] = [0, 0];
@@ -95,7 +97,7 @@ async function detectHands(input: Tensor, config: Config): Promise<HandDetectRes
   if (!input || !models[0]) return hands;
   const t: Record<string, Tensor> = {};
   const ratio = (input.shape[2] || 1) / (input.shape[1] || 1);
-  const height = Math.min(Math.round((input.shape[1] || 0) / 8) * 8, 512); // use dynamic input size but cap at 512
+  const height = Math.min(Math.round((input.shape[1] || 0) / 8) * 8, maxDetectorResolution); // use dynamic input size but cap at 512
   const width = Math.round(height * ratio / 8) * 8;
   t.resize = tf.image.resizeBilinear(input, [height, width]); // todo: resize with padding
   t.cast = tf.cast(t.resize, 'int32');
@@ -117,12 +119,13 @@ async function detectHands(input: Tensor, config: Config): Promise<HandDetectRes
     const boxSlice = tf.slice(t.boxes, nmsIndex, 1);
     const boxData = await boxSlice.data();
     tf.dispose(boxSlice);
-    const boxInput: Box = [boxData[1], boxData[0], boxData[3] - boxData[1], boxData[2] - boxData[0]];
-    const boxRaw: Box = box.scale(boxInput, 1.2); // handtrack model returns tight box so we expand it a bit
-    const boxFull: Box = [Math.trunc(boxRaw[0] * outputSize[0]), Math.trunc(boxRaw[1] * outputSize[1]), Math.trunc(boxRaw[2] * outputSize[0]), Math.trunc(boxRaw[3] * outputSize[1])];
+    const boxSquareSize = Math.max(boxData[3] - boxData[1], boxData[2] - boxData[0]);
+    const boxRaw: Box = box.scale([boxData[1], boxData[0], boxSquareSize, boxSquareSize], detectorExpandFact); // for raw box we use squared and expanded box
+    const boxCrop: Box = box.crop(boxRaw); // crop box is based on raw box
+    const boxFull: Box = [Math.trunc(boxData[1] * outputSize[0]), Math.trunc(boxData[0] * outputSize[1]), Math.trunc((boxData[3] - boxData[1]) * outputSize[0]), Math.trunc((boxData[2] - boxData[0]) * outputSize[1])]; // for box we keep original scaled values
     const score = scores[nmsIndex];
     const label = classes[classNum[nmsIndex]];
-    const hand: HandDetectResult = { id: id++, score, box: boxFull, boxRaw, boxCrop: box.crop(boxRaw), label };
+    const hand: HandDetectResult = { id: id++, score, box: boxFull, boxRaw, boxCrop, label };
     hands.push(hand);
   }
   Object.keys(t).forEach((tensor) => tf.dispose(t[tensor]));
@@ -146,7 +149,7 @@ async function detectFingers(input: Tensor, h: HandDetectResult, config: Config)
   };
   if (input && models[1] && config.hand.landmarks && h.score > (config.hand.minConfidence || 0)) {
     const t: Record<string, Tensor> = {};
-    t.crop = tf.image.cropAndResize(input, [box.crop(h.boxRaw)], [0], [inputSize[1][0], inputSize[1][1]], 'bilinear');
+    t.crop = tf.image.cropAndResize(input, [h.boxCrop], [0], [inputSize[1][0], inputSize[1][1]], 'bilinear');
     t.cast = tf.cast(t.crop, 'float32');
     t.div = tf.div(t.cast, 255);
     [t.score, t.keypoints] = models[1].execute(t.div) as Tensor[];
@@ -155,12 +158,17 @@ async function detectFingers(input: Tensor, h: HandDetectResult, config: Config)
     if (score >= (config.hand.minConfidence || 0)) {
       hand.fingerScore = score;
       t.reshaped = tf.reshape(t.keypoints, [-1, 3]);
-      const rawCoords = await t.reshaped.array() as Point[];
-      hand.keypoints = (rawCoords as Point[]).map((kpt) => [
-        outputSize[0] * ((h.boxCrop[3] - h.boxCrop[1]) * kpt[0] / inputSize[1][0] + h.boxCrop[1]),
-        outputSize[1] * ((h.boxCrop[2] - h.boxCrop[0]) * kpt[1] / inputSize[1][1] + h.boxCrop[0]),
-        (h.boxCrop[3] + h.boxCrop[3] / 2 * (kpt[2] || 0)),
+      const coordsData: Point[] = await t.reshaped.array() as Point[];
+      const coordsRaw: Point[] = coordsData.map((kpt) => [kpt[0] / inputSize[1][1], kpt[1] / inputSize[1][0], (kpt[2] || 0)]);
+      const coordsNorm: Point[] = coordsRaw.map((kpt) => [kpt[0] * h.boxRaw[2], kpt[1] * h.boxRaw[3], (kpt[2] || 0)]);
+      console.log(outputSize, h.box);
+      hand.keypoints = (coordsNorm).map((kpt) => [
+        outputSize[0] * kpt[0] + h.box[0],
+        outputSize[1] * kpt[1] + h.box[1],
+        (kpt[2] || 0),
       ]);
+      // hand.box = box.scale(h.box, 1 / detectorExpandFact); // scale box down for visual appeal
+      // hand.boxRaw = box.scale(h.boxRaw, 1 / detectorExpandFact); // scale box down for visual appeal
       hand.landmarks = fingerPose.analyze(hand.keypoints) as HandResult['landmarks']; // calculate finger landmarks
       for (const key of Object.keys(fingerMap)) { // map keypoints to per-finger annotations
         hand.annotations[key] = fingerMap[key].map((index) => (hand.landmarks && hand.keypoints[index] ? hand.keypoints[index] : null));
@@ -171,15 +179,27 @@ async function detectFingers(input: Tensor, h: HandDetectResult, config: Config)
   return hand;
 }
 
+let n = 0;
 export async function predict(input: Tensor, config: Config): Promise<HandResult[]> {
+  n++;
+  /** handtrack caching
+   * 1. if skipFrame returned cached
+   * 2. if any cached results but although not sure if its enough we continute anyhow for 10x skipframes
+   * 3. eventually rerun detector to generated new cached boxes and reset skipped
+   * 4. generate cached boxes based on detected keypoints
+   */
   if (!models[0] || !models[1] || !models[0]?.inputs[0].shape || !models[1]?.inputs[0].shape) return []; // something is wrong with the model
   outputSize = [input.shape[2] || 0, input.shape[1] || 0];
 
   skipped++; // increment skip frames
   if (config.skipFrame && (skipped <= (config.hand.skipFrames || 0))) {
+    console.log(n, 'SKIP', { results: cache.hands.length });
     return cache.hands; // return cached results without running anything
   }
   return new Promise(async (resolve) => {
+    console.log(n, 'DETECT', { skipped, hands: cache.hands.length, boxes: cache.boxes.length });
+    // this is logically consistent but insufficiently efficient
+    /*
     skipped = 0;
     if (cache.boxes.length >= (config.hand.maxDetected || 0)) {
       cache.hands = await Promise.all(cache.boxes.map((handBox) => detectFingers(input, handBox, config))); // if we have enough cached boxes run detection using cache
@@ -191,17 +211,32 @@ export async function predict(input: Tensor, config: Config): Promise<HandResult
       cache.boxes = await detectHands(input, config);
       cache.hands = await Promise.all(cache.boxes.map((handBox) => detectFingers(input, handBox, config)));
     }
+    */
+
+    if (config.skipFrame && skipped <= 10 * (config.hand.skipFrames || 0) && cache.hands.length > 0) { // we have some cached results but although not sure if its enough we continute anyhow for 10x skipframes
+      cache.hands = await Promise.all(cache.boxes.map((handBox) => detectFingers(input, handBox, config)));
+      console.log(n, 'HANDS', { hands: cache.hands.length });
+    } else {
+      cache.boxes = await detectHands(input, config);
+      console.log(n, 'BOXES', { hands: cache.boxes.length });
+      cache.hands = await Promise.all(cache.boxes.map((handBox) => detectFingers(input, handBox, config)));
+      console.log(n, 'HANDS', { hands: cache.hands.length });
+      skipped = 0;
+    }
 
     const oldCache = [...cache.boxes];
     cache.boxes.length = 0; // reset cache
-    for (let i = 0; i < cache.hands.length; i++) {
-      const boxKpt = box.square(cache.hands[i].keypoints, outputSize);
-      if (boxKpt.box[2] / (input.shape[2] || 1) > 0.05 && boxKpt.box[3] / (input.shape[1] || 1) > 0.05 && cache.hands[i].fingerScore && cache.hands[i].fingerScore > (config.hand.minConfidence || 0)) {
-        const boxScale = box.scale(boxKpt.box, boxExpandFact);
-        const boxScaleRaw = box.scale(boxKpt.boxRaw, boxExpandFact);
-        const boxCrop = box.crop(boxScaleRaw);
-        cache.boxes.push({ ...oldCache[i], box: boxScale, boxRaw: boxScaleRaw, boxCrop });
+    if (config.cacheSensitivity > 0) {
+      for (let i = 0; i < cache.hands.length; i++) {
+        const boxKpt = box.square(cache.hands[i].keypoints, outputSize);
+        if (boxKpt.box[2] / (input.shape[2] || 1) > 0.05 && boxKpt.box[3] / (input.shape[1] || 1) > 0.05 && cache.hands[i].fingerScore && cache.hands[i].fingerScore > (config.hand.minConfidence || 0)) {
+          const boxScale = box.scale(boxKpt.box, boxExpandFact);
+          const boxScaleRaw = box.scale(boxKpt.boxRaw, boxExpandFact);
+          const boxCrop = box.crop(boxScaleRaw);
+          cache.boxes.push({ ...oldCache[i], box: boxScale, boxRaw: boxScaleRaw, boxCrop });
+        }
       }
+      console.log(n, 'CACHED', { hands: cache.boxes.length });
     }
     resolve(cache.hands);
   });

src/human.ts

@@ -265,8 +265,8 @@ export class Human {
    * @param input: {@link Input}
    * @returns { tensor, canvas }
    */
-  image(input: Input) {
-    return image.process(input, this.config);
+  image(input: Input, getTensor: boolean = true) {
+    return image.process(input, this.config, getTensor);
   }
 
   /** Segmentation method takes any input and returns processed canvas with body segmentation

src/image/image.ts

@@ -13,8 +13,8 @@ export type Input = Tensor | ImageData | ImageBitmap | HTMLImageElement | HTMLMe
 
 const maxSize = 2048;
 // internal temp canvases
-let inCanvas;
-let outCanvas;
+let inCanvas: HTMLCanvasElement | OffscreenCanvas | null = null; // use global variable to avoid recreating canvas on each frame
+let outCanvas: HTMLCanvasElement | OffscreenCanvas | null = null; // use global variable to avoid recreating canvas on each frame
 // @ts-ignore // imagefx is js module that should be converted to a class
 let fx: fxImage.GLImageFilter | null; // instance of imagefx
 
@@ -38,11 +38,17 @@ export function canvas(width, height): HTMLCanvasElement | OffscreenCanvas {
   return c;
 }
 
+export function copy(input: HTMLCanvasElement | OffscreenCanvas, output?: HTMLCanvasElement | OffscreenCanvas) {
+  const outputCanvas = output || canvas(input.width, input.height);
+  const ctx = outputCanvas.getContext('2d') as CanvasRenderingContext2D;
+  ctx.drawImage(input, 0, 0);
+  return outputCanvas;
+}
+
 // process input image and return tensor
 // input can be tensor, imagedata, htmlimageelement, htmlvideoelement
 // input is resized and run through imagefx filter
-export function process(input: Input, config: Config): { tensor: Tensor | null, canvas: OffscreenCanvas | HTMLCanvasElement | null } {
-  let tensor;
+export function process(input: Input, config: Config, getTensor: boolean = true): { tensor: Tensor | null, canvas: OffscreenCanvas | HTMLCanvasElement | null } {
   if (!input) {
     // throw new Error('input is missing');
     if (config.debug) log('input is missing');
@@ -66,9 +72,9 @@ export function process(input: Input, config: Config): { tensor: Tensor | null,
   }
   if (input instanceof tf.Tensor) {
     // if input is tensor, use as-is
-    if ((input as Tensor)['isDisposedInternal']) throw new Error('input tensor is disposed');
-    if ((input as Tensor).shape && (input as Tensor).shape.length === 4 && (input as unknown as Tensor).shape[0] === 1 && (input as unknown as Tensor).shape[3] === 3) tensor = tf.clone(input);
-    else throw new Error(`input tensor shape must be [1, height, width, 3] and instead was ${(input as Tensor).shape}`);
+    if ((input)['isDisposedInternal']) throw new Error('input tensor is disposed');
+    else if (!input.shape || input.shape.length !== 4 || input.shape[0] !== 1 || input.shape[3] !== 3) throw new Error(`input tensor shape must be [1, height, width, 3] and instead was ${input.shape}`);
+    else return { tensor: tf.clone(input), canvas: (config.filter.return ? outCanvas : null) };
   } else {
     // check if resizing will be needed
     if (typeof input['readyState'] !== 'undefined' && input['readyState'] <= 2) {
@@ -101,28 +107,26 @@ export function process(input: Input, config: Config): { tensor: Tensor | null,
     if (!inCanvas || (inCanvas?.width !== targetWidth) || (inCanvas?.height !== targetHeight)) inCanvas = canvas(targetWidth, targetHeight);
 
     // draw input to our canvas
-    const ctx = inCanvas.getContext('2d');
+    const inCtx = inCanvas.getContext('2d') as CanvasRenderingContext2D;
     if ((typeof ImageData !== 'undefined') && (input instanceof ImageData)) {
-      ctx.putImageData(input, 0, 0);
+      inCtx.putImageData(input, 0, 0);
     } else {
-      if (config.filter.flip && typeof ctx.translate !== 'undefined') {
-        ctx.translate(originalWidth, 0);
-        ctx.scale(-1, 1);
-        ctx.drawImage(input, 0, 0, originalWidth, originalHeight, 0, 0, inCanvas?.width, inCanvas?.height);
-        ctx.setTransform(1, 0, 0, 1, 0, 0); // resets transforms to defaults
+      if (config.filter.flip && typeof inCtx.translate !== 'undefined') {
+        inCtx.translate(originalWidth, 0);
+        inCtx.scale(-1, 1);
+        inCtx.drawImage(input as CanvasImageSource, 0, 0, originalWidth, originalHeight, 0, 0, inCanvas?.width, inCanvas?.height);
+        inCtx.setTransform(1, 0, 0, 1, 0, 0); // resets transforms to defaults
       } else {
-        ctx.drawImage(input, 0, 0, originalWidth, originalHeight, 0, 0, inCanvas?.width, inCanvas?.height);
+        inCtx.drawImage(input as CanvasImageSource, 0, 0, originalWidth, originalHeight, 0, 0, inCanvas?.width, inCanvas?.height);
       }
     }
-    // imagefx transforms using gl
+
+    if (!outCanvas || (inCanvas.width !== outCanvas.width) || (inCanvas?.height !== outCanvas?.height)) outCanvas = canvas(inCanvas.width, inCanvas.height); // init output canvas
+
+    // imagefx transforms using gl from input canvas to output canvas
     if (config.filter.enabled && env.webgl.supported) {
-      if (!fx || !outCanvas || (inCanvas.width !== outCanvas.width) || (inCanvas?.height !== outCanvas?.height)) {
-        outCanvas = canvas(inCanvas?.width, inCanvas?.height);
-        if (outCanvas?.width !== inCanvas?.width) outCanvas.width = inCanvas?.width;
-        if (outCanvas?.height !== inCanvas?.height) outCanvas.height = inCanvas?.height;
-        // log('created FX filter');
-        fx = env.browser ? new fxImage.GLImageFilter({ canvas: outCanvas }) : null; // && (typeof document !== 'undefined')
-      }
+      if (!fx) fx = env.browser ? new fxImage.GLImageFilter({ canvas: outCanvas }) : null; // && (typeof document !== 'undefined')
+      env.filter = !!fx;
       if (!fx) return { tensor: null, canvas: inCanvas };
       fx.reset();
       fx.addFilter('brightness', config.filter.brightness); // must have at least one filter enabled
@@ -140,118 +144,105 @@ export function process(input: Input, config: Config): { tensor: Tensor | null,
       if (config.filter.polaroid) fx.addFilter('polaroid');
       if (config.filter.pixelate !== 0) fx.addFilter('pixelate', config.filter.pixelate);
       fx.apply(inCanvas);
-      // read pixel data
-      /*
-      const gl = outCanvas.getContext('webgl');
-      if (gl) {
-        const glBuffer = new Uint8Array(outCanvas.width * outCanvas.height * 4);
-        const pixBuffer = new Uint8Array(outCanvas.width * outCanvas.height * 3);
-        gl.readPixels(0, 0, outCanvas.width, outCanvas.height, gl.RGBA, gl.UNSIGNED_BYTE, glBuffer);
-        // gl returns rbga while we only need rgb, so discarding alpha channel
-        // gl returns starting point as lower left, so need to invert vertical
-        let i = 0;
-        for (let y = outCanvas.height - 1; y >= 0; y--) {
-          for (let x = 0; x < outCanvas.width; x++) {
-            const index = (x + y * outCanvas.width) * 4;
-            pixBuffer[i++] = glBuffer[index + 0];
-            pixBuffer[i++] = glBuffer[index + 1];
-            pixBuffer[i++] = glBuffer[index + 2];
-          }
-        }
-        outCanvas.data = pixBuffer;
-        const shape = [outCanvas.height, outCanvas.width, 3];
-        const pixels = tf.tensor3d(outCanvas.data, shape, 'float32');
-        tensor = tf.expandDims(pixels, 0);
-        tf.dispose(pixels);
-      }
-      */
     } else {
-      outCanvas = inCanvas;
+      copy(inCanvas, outCanvas); // if no filters applied, output canvas is input canvas
       if (fx) fx = null;
+      env.filter = !!fx;
     }
-    // create tensor from image if tensor is not already defined
-    if (!tensor) {
-      let pixels;
-      if (outCanvas.data) { // if we have data, just convert to tensor
-        const shape = [outCanvas.height, outCanvas.width, 3];
-        pixels = tf.tensor3d(outCanvas.data, shape, 'float32');
-      } else if ((typeof ImageData !== 'undefined') && (outCanvas instanceof ImageData)) { // if input is imagedata, just use it
-        pixels = tf.browser ? tf.browser.fromPixels(outCanvas) : null;
-      } else if (config.backend === 'webgl' || config.backend === 'humangl') { // tf kernel-optimized method to get imagedata
-        // we cant use canvas as-is as it already has a context, so we do a silly one more canvas
-        const tempCanvas = canvas(targetWidth, targetHeight);
-        tempCanvas.width = targetWidth;
-        tempCanvas.height = targetHeight;
-        const tempCtx = tempCanvas.getContext('2d');
-        tempCtx?.drawImage(outCanvas, 0, 0);
-        try {
-          pixels = (tf.browser && env.browser) ? tf.browser.fromPixels(tempCanvas) : null;
-        } catch (err) {
-          throw new Error('browser webgl error');
-        }
-      } else { // cpu and wasm kernel does not implement efficient fromPixels method
-        // we cant use canvas as-is as it already has a context, so we do a silly one more canvas and do fromPixels on ImageData instead
-        const tempCanvas = canvas(targetWidth, targetHeight);
-        if (!tempCanvas) return { tensor: null, canvas: inCanvas };
-        tempCanvas.width = targetWidth;
-        tempCanvas.height = targetHeight;
-        const tempCtx = tempCanvas.getContext('2d');
-        if (!tempCtx) return { tensor: null, canvas: inCanvas };
-        tempCtx.drawImage(outCanvas, 0, 0);
-        const data = tempCtx.getImageData(0, 0, targetWidth, targetHeight);
-        if (tf.browser && env.browser) {
-          pixels = tf.browser.fromPixels(data);
-        } else {
-          pixels = tf.tidy(() => {
-            const imageData = tf.tensor(Array.from(data.data), [targetWidth, targetHeight, 4]);
-            const channels = tf.split(imageData, 4, 2); // split rgba to channels
-            const rgb = tf.stack([channels[0], channels[1], channels[2]], 2); // stack channels back to rgb and ignore alpha
-            const expand = tf.reshape(rgb, [imageData.shape[0], imageData.shape[1], 3]); // move extra dim from the end of tensor and use it as batch number instead
-            return expand;
-          });
-        }
-      }
-      if (pixels) {
-        const casted = tf.cast(pixels, 'float32');
-        tensor = tf.expandDims(casted, 0);
-        tf.dispose(pixels);
-        tf.dispose(casted);
+
+    if (!getTensor) return { tensor: null, canvas: outCanvas }; // just canvas was requested
+
+    // create tensor from image unless input was a tensor already
+    let pixels;
+    let depth = 3;
+    if ((typeof ImageData !== 'undefined' && input instanceof ImageData) || (input['data'] && input['width'] && input['height'])) { // if input is imagedata, just use it
+      if (env.browser && tf.browser) {
+        pixels = tf.browser ? tf.browser.fromPixels(input) : null;
       } else {
-        tensor = tf.zeros([1, targetWidth, targetHeight, 3]);
-        throw new Error('cannot create tensor from input');
+        depth = input['data'].length / input['height'] / input['width'];
+        // const arr = Uint8Array.from(input['data']);
+        const arr = new Uint8Array(input['data']['buffer']);
+        pixels = tf.tensor(arr, [input['height'], input['width'], depth], 'float32');
+      }
+    } else {
+      if (tf.browser && env.browser) {
+        if (config.backend === 'webgl' || config.backend === 'humangl' || config.backend === 'webgpu') {
+          pixels = tf.browser.fromPixels(outCanvas); // safe to reuse since both backend and context are gl based
+        } else {
+          const tempCanvas = copy(outCanvas); // cannot use output canvas as it already has gl context so we do a silly one more canvas
+          pixels = tf.browser.fromPixels(tempCanvas);
+        }
+      } else {
+        const tempCanvas = copy(outCanvas); // cannot use output canvas as it already has gl context so we do a silly one more canvas
+        const tempCtx = tempCanvas.getContext('2d') as CanvasRenderingContext2D;
+        const tempData = tempCtx.getImageData(0, 0, targetWidth, targetHeight);
+        depth = input['data'].length / targetWidth / targetHeight;
+        const arr = new Uint8Array(tempData.data.buffer);
+        pixels = tf.tensor(arr, [targetWidth, targetHeight, depth]);
       }
     }
+    if (depth === 4) { // rgba to rgb
+      const rgb = tf.slice3d(pixels, [0, 0, 0], [-1, -1, 3]); // strip alpha channel
+      tf.dispose(pixels);
+      pixels = rgb;
+      /*
+      const channels = tf.split(pixels, 4, 2); // split rgba to channels
+      tf.dispose(pixels);
+      const rgb = tf.stack([channels[0], channels[1], channels[2]], 2); // stack channels back to rgb and ignore alpha
+      pixels = tf.reshape(rgb, [rgb.shape[0], rgb.shape[1], 3]); // move extra dim from the end of tensor and use it as batch number instead
+      tf.dispose([rgb, ...channels]);
+      */
+    }
+    if (!pixels) throw new Error('cannot create tensor from input');
+    const casted = tf.cast(pixels, 'float32');
+    const tensor = tf.expandDims(casted, 0);
+    tf.dispose([pixels, casted]);
+    return { tensor, canvas: (config.filter.return ? outCanvas : null) };
   }
-  return { tensor, canvas: (config.filter.return ? outCanvas : null) };
 }
 
 let lastInputSum = 0;
 let lastCacheDiff = 1;
+let benchmarked = 0;
+
+const checksum = async (input: Tensor): Promise<number> => { // use tf sum or js based sum loop depending on which is faster
+  const resizeFact = 48;
+  const reduced: Tensor = tf.image.resizeBilinear(input, [Math.trunc((input.shape[1] || 1) / resizeFact), Math.trunc((input.shape[2] || 1) / resizeFact)]);
+  const tfSum = async (): Promise<number> => {
+    const sumT = tf.sum(reduced);
+    const sum0 = await sumT.data();
+    tf.dispose(sumT);
+    return sum0[0];
+  };
+  const jsSum = async (): Promise<number> => {
+    const reducedData = await reduced.data(); // raw image rgb array
+    let sum0 = 0;
+    for (let i = 0; i < reducedData.length / 3; i++) sum0 += reducedData[3 * i + 2]; // look only at green value of each pixel
+    return sum0;
+  };
+  if (benchmarked === 0) {
+    const t0 = performance.now();
+    await jsSum();
+    const t1 = performance.now();
+    await tfSum();
+    const t2 = performance.now();
+    benchmarked = t1 - t0 < t2 - t1 ? 1 : 2;
+  }
+  const res = benchmarked === 1 ? await jsSum() : await tfSum();
+  tf.dispose(reduced);
+  return res;
+};
+
 export async function skip(config, input: Tensor) {
   if (config.cacheSensitivity === 0) return false;
-  const resizeFact = 32;
-  if (!input.shape[1] || !input.shape[2]) return false;
-  const reduced: Tensor = tf.image.resizeBilinear(input, [Math.trunc(input.shape[1] / resizeFact), Math.trunc(input.shape[2] / resizeFact)]);
-
-  // use tensor sum
-  /*
-  const sumT = this.tf.sum(reduced);
-  const sum = await sumT.data()[0] as number;
-  sumT.dispose();
-  */
-  // use js loop sum, faster than uploading tensor to gpu calculating and downloading back
-  const reducedData = await reduced.data(); // raw image rgb array
-  tf.dispose(reduced);
-  let sum = 0;
-  for (let i = 0; i < reducedData.length / 3; i++) sum += reducedData[3 * i + 2]; // look only at green value of each pixel
-
+  const sum = await checksum(input);
   const diff = 100 * (Math.max(sum, lastInputSum) / Math.min(sum, lastInputSum) - 1);
   lastInputSum = sum;
   // if previous frame was skipped, skip this frame if changed more than cacheSensitivity
   // if previous frame was not skipped, then look for cacheSensitivity or difference larger than one in previous frame to avoid resetting cache in subsequent frames unnecessarily
-  const skipFrame = diff < Math.max(config.cacheSensitivity, lastCacheDiff);
+  let skipFrame = diff < Math.max(config.cacheSensitivity, lastCacheDiff);
   // if difference is above 10x threshold, don't use last value to force reset cache for significant change of scenes or images
   lastCacheDiff = diff > 10 * config.cacheSensitivity ? 0 : diff;
-  // console.log('skipFrame', skipFrame, this.config.cacheSensitivity, diff);
+  skipFrame = skipFrame && (lastCacheDiff > 0); // if no cached diff value then force no skip
   return skipFrame;
 }

src/util/box.ts

@@ -21,8 +21,13 @@ export function square(keypoints: Array<Point>, outputSize: [number, number] = [
 }
 
 export function scale(box: Box, scaleFact: number) {
-  const dist = [box[2] * (scaleFact - 1), box[3] * (scaleFact - 1)];
-  const newBox: Box = [box[0] - dist[0] / 2, box[1] - dist[1] / 2, box[2] + dist[0], box[3] + dist[0]];
+  const dist = [box[2] * scaleFact, box[3] * scaleFact];
+  const newBox: Box = [
+    box[0] - (dist[0] - box[2]) / 2,
+    box[1] - (dist[1] - box[3]) / 2,
+    dist[0],
+    dist[1],
+  ];
   return newBox;
 }
 

src/util/env.ts

@@ -1,39 +1,57 @@
 import * as tf from '../../dist/tfjs.esm.js';
 import * as image from '../image/image';
-import { mergeDeep, log } from './util';
+import { mergeDeep } from './util';
 
 export type Env = {
+  /** Running in Browser */
   browser: undefined | boolean,
+  /** Running in NodeJS */
   node: undefined | boolean,
+  /** Running in WebWorker thread */
   worker: undefined | boolean,
+  /** Detected platform */
   platform: undefined | string,
+  /** Detected agent */
   agent: undefined | string,
+  /** List of supported backends */
   backends: string[],
+  /** Has any work been performed so far */
   initial: boolean,
+  /** Are image filters supported? */
+  filter: undefined | boolean,
+  /** TFJS instance details */
   tfjs: {
     version: undefined | string,
   },
+  /** Is offscreenCanvas supported? */
   offscreen: undefined | boolean,
+  /** WASM detected capabilities */
   wasm: {
     supported: undefined | boolean,
     backend: undefined | boolean,
     simd: undefined | boolean,
     multithread: undefined | boolean,
   },
+  /** WebGL detected capabilities */
   webgl: {
     supported: undefined | boolean,
     backend: undefined | boolean,
     version: undefined | string,
     renderer: undefined | string,
   },
+  /** WebGPU detected capabilities */
   webgpu: {
     supported: undefined | boolean,
     backend: undefined | boolean,
     adapter: undefined | string,
   },
+  /** List of supported kernels for current backend */
   kernels: string[],
+  /** MonkeyPatch for Canvas */
   Canvas: undefined,
+  /** MonkeyPatch for Image */
   Image: undefined,
+  /** MonkeyPatch for ImageData */
   ImageData: undefined,
 }
 
@@ -47,6 +65,7 @@ export let env: Env = {
   initial: true,
   backends: [],
   offscreen: undefined,
+  filter: undefined,
   tfjs: {
     version: undefined,
   },
@@ -144,12 +163,14 @@ export async function get() {
       env.agent = env.agent.replace(/  /g, ' ');
 
       // chrome offscreencanvas gpu memory leak
+      /*
       const isChrome = env.agent.match(/Chrome\/.[0-9]/g);
       const verChrome = isChrome && isChrome[0] ? isChrome[0].split('/')[1] : 0;
       if (verChrome > 0 && verChrome > 92 && verChrome < 96) {
         log('disabling offscreenCanvas due to browser error:', isChrome ? isChrome[0] : 'unknown');
         env.offscreen = false;
       }
+      */
     }
   } else if (typeof process !== 'undefined') {
     env.platform = `${process.platform} ${process.arch}`;