diff --git a/CHANGELOG.md b/CHANGELOG.md
index 86855d34..1c582f24 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,7 +9,7 @@ Repository: **<git+https://github.com/vladmandic/human.git>**
 
 ## Changelog
 
-### **HEAD -> main** 2021/08/06 mandic00@live.com
+### **HEAD -> main** 2021/08/09 mandic00@live.com
 
 - minor update
 - replace movenet with lightning-v4
diff --git a/demo/index.js b/demo/index.js
index e2e8316d..e0e3b465 100644
--- a/demo/index.js
+++ b/demo/index.js
@@ -40,15 +40,15 @@ let userConfig = {
     enabled: false,
     flip: false,
   },
-  face: { enabled: false,
-    detector: { return: true },
+  face: { enabled: true,
+    detector: { return: false },
     mesh: { enabled: true },
     iris: { enabled: false },
     description: { enabled: false },
     emotion: { enabled: false },
   },
   object: { enabled: false },
-  gesture: { enabled: true },
+  gesture: { enabled: false },
   hand: { enabled: false },
   body: { enabled: false },
   // body: { enabled: true, modelPath: 'posenet.json' },
@@ -164,7 +164,8 @@ function status(msg) {
     div.innerText = msg;
   } else {
     const video = document.getElementById('video');
-    document.getElementById('play').style.display = (video.srcObject !== null) && !video.paused ? 'none' : 'block';
+    const playing = (video.srcObject !== null) && !video.paused;
+    document.getElementById('play').style.display = playing ? 'none' : 'block';
     document.getElementById('loader').style.display = 'none';
     div.innerText = '';
   }
@@ -259,9 +260,10 @@ async function drawResults(input) {
   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 ? `backend: ${human.tf.getBackend()} | ${memory}` : 'running in web worker';
   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: ${human.tf.getBackend()} | ${memory}<br>
+    backend: ${backend}<br>
     performance: ${str(lastDetectedResult.performance)}ms ${fps}<br>
     ${warning}<br>
   `;
@@ -363,6 +365,7 @@ async function setupCamera() {
       // eslint-disable-next-line no-use-before-define
       if (live && !ui.detectThread) runHumanDetect(video, canvas);
       ui.busy = false;
+      status();
       resolve();
     };
   });
@@ -597,6 +600,7 @@ async function detectVideo() {
       document.getElementById('btnStartText').innerHTML = 'pause video';
       await video.play();
       runHumanDetect(video, canvas);
+      status();
     } else {
       status(cameraError);
     }
@@ -878,6 +882,7 @@ async function pwaRegister() {
 }
 
 async function main() {
+  /*
   window.addEventListener('unhandledrejection', (evt) => {
     // eslint-disable-next-line no-console
     console.error(evt.reason || evt);
@@ -885,6 +890,7 @@ async function main() {
     status('exception error');
     evt.preventDefault();
   });
+  */
 
   log('demo starting ...');
 
diff --git a/package.json b/package.json
index 1bfee12e..780ddae7 100644
--- a/package.json
+++ b/package.json
@@ -59,15 +59,16 @@
     "@tensorflow/tfjs-backend-cpu": "^3.8.0",
     "@tensorflow/tfjs-backend-wasm": "^3.8.0",
     "@tensorflow/tfjs-backend-webgl": "^3.8.0",
+    "@tensorflow/tfjs-backend-webgpu": "^0.0.1-alpha.7",
     "@tensorflow/tfjs-converter": "^3.8.0",
     "@tensorflow/tfjs-core": "^3.8.0",
     "@tensorflow/tfjs-data": "^3.8.0",
     "@tensorflow/tfjs-layers": "^3.8.0",
     "@tensorflow/tfjs-node": "^3.8.0",
     "@tensorflow/tfjs-node-gpu": "^3.8.0",
-    "@types/node": "^16.4.13",
-    "@typescript-eslint/eslint-plugin": "^4.29.0",
-    "@typescript-eslint/parser": "^4.29.0",
+    "@types/node": "^16.4.14",
+    "@typescript-eslint/eslint-plugin": "^4.29.1",
+    "@typescript-eslint/parser": "^4.29.1",
     "@vladmandic/pilogger": "^0.2.18",
     "canvas": "^2.8.0",
     "chokidar": "^3.5.2",
diff --git a/src/face.ts b/src/face.ts
index 6473fa4f..dcf7fc08 100644
--- a/src/face.ts
+++ b/src/face.ts
@@ -163,8 +163,8 @@ export const detectFace = async (parent /* instance of human */, input: Tensor):
 
     // is something went wrong, skip the face
     // @ts-ignore possibly undefined
-    if (!faces[i].image || faces[i].image['isDisposedInternal']) {
-      log('Face object is disposed:', faces[i].image);
+    if (!faces[i].tensor || faces[i].tensor['isDisposedInternal']) {
+      log('Face object is disposed:', faces[i].tensor);
       continue;
     }
 
@@ -173,11 +173,11 @@ export const detectFace = async (parent /* instance of human */, input: Tensor):
     // run emotion, inherits face from blazeface
     parent.analyze('Start Emotion:');
     if (parent.config.async) {
-      emotionRes = parent.config.face.emotion.enabled ? emotion.predict(faces[i].image || tf.tensor([]), parent.config, i, faces.length) : {};
+      emotionRes = parent.config.face.emotion.enabled ? emotion.predict(faces[i].tensor || tf.tensor([]), parent.config, i, faces.length) : {};
     } else {
       parent.state = 'run:emotion';
       timeStamp = now();
-      emotionRes = parent.config.face.emotion.enabled ? await emotion.predict(faces[i].image || tf.tensor([]), parent.config, i, faces.length) : {};
+      emotionRes = parent.config.face.emotion.enabled ? await emotion.predict(faces[i].tensor || tf.tensor([]), parent.config, i, faces.length) : {};
       parent.performance.emotion = Math.trunc(now() - timeStamp);
     }
     parent.analyze('End Emotion:');
@@ -186,11 +186,11 @@ export const detectFace = async (parent /* instance of human */, input: Tensor):
     /*
     parent.analyze('Start GEAR:');
     if (parent.config.async) {
-      gearRes = parent.config.face.agegenderrace.enabled ? agegenderrace.predict(faces[i].image || tf.tensor([]), parent.config, i, faces.length) : {};
+      gearRes = parent.config.face.agegenderrace.enabled ? agegenderrace.predict(faces[i].tensor || tf.tensor([]), parent.config, i, faces.length) : {};
     } else {
       parent.state = 'run:gear';
       timeStamp = now();
-      gearRes = parent.config.face.agegenderrace.enabled ? await agegenderrace.predict(faces[i].image || tf.tensor([]), parent.config, i, faces.length) : {};
+      gearRes = parent.config.face.agegenderrace.enabled ? await agegenderrace.predict(faces[i].tensor || tf.tensor([]), parent.config, i, faces.length) : {};
       parent.performance.emotion = Math.trunc(now() - timeStamp);
     }
     parent.analyze('End GEAR:');
@@ -199,11 +199,11 @@ export const detectFace = async (parent /* instance of human */, input: Tensor):
     // run emotion, inherits face from blazeface
     parent.analyze('Start Description:');
     if (parent.config.async) {
-      descRes = parent.config.face.description.enabled ? faceres.predict(faces[i].image || tf.tensor([]), parent.config, i, faces.length) : [];
+      descRes = parent.config.face.description.enabled ? faceres.predict(faces[i].tensor || tf.tensor([]), parent.config, i, faces.length) : [];
     } else {
       parent.state = 'run:description';
       timeStamp = now();
-      descRes = parent.config.face.description.enabled ? await faceres.predict(faces[i].image || tf.tensor([]), parent.config, i, faces.length) : [];
+      descRes = parent.config.face.description.enabled ? await faceres.predict(faces[i].tensor || tf.tensor([]), parent.config, i, faces.length) : [];
       parent.performance.embedding = Math.trunc(now() - timeStamp);
     }
     parent.analyze('End Description:');
@@ -226,6 +226,12 @@ export const detectFace = async (parent /* instance of human */, input: Tensor):
       ? Math.max(Math.abs(faces[i].annotations.leftEyeIris[3][0] - faces[i].annotations.leftEyeIris[1][0]), Math.abs(faces[i].annotations.rightEyeIris[4][1] - faces[i].annotations.rightEyeIris[2][1])) / input.shape[2]
       : 0;
 
+    // optionally return tensor
+    const tensor = parent.config.face.detector.return ? tf.squeeze(faces[i].tensor) : null;
+    // dispose original face tensor
+    tf.dispose(faces[i].tensor);
+    // delete temp face image
+    if (faces[i].tensor) delete faces[i].tensor;
     // combine results
     faceRes.push({
       ...faces[i],
@@ -237,12 +243,8 @@ export const detectFace = async (parent /* instance of human */, input: Tensor):
       emotion: emotionRes,
       iris: irisSize !== 0 ? Math.trunc(500 / irisSize / 11.7) / 100 : 0,
       rotation,
-      tensor: parent.config.face.detector.return ? tf.squeeze(faces[i].image) : null,
+      tensor,
     });
-    // dispose original face tensor
-    tf.dispose(faces[i].image);
-    // delete temp face image
-    if (faces[i].image) delete faces[i].image;
 
     parent.analyze('End Face');
   }
diff --git a/src/handpose/handdetector.ts b/src/handpose/handdetector.ts
index 88813eae..e0ce14d4 100644
--- a/src/handpose/handdetector.ts
+++ b/src/handpose/handdetector.ts
@@ -50,7 +50,7 @@ export class HandDetector {
     const boxes = this.normalizeBoxes(rawBoxes);
     tf.dispose(rawBoxes);
     const filteredT = await tf.image.nonMaxSuppressionAsync(boxes, scores, config.hand.maxDetected, config.hand.iouThreshold, config.hand.minConfidence);
-    const filtered = filteredT.arraySync();
+    const filtered = await filteredT.array();
 
     tf.dispose(scoresT);
     tf.dispose(filteredT);
@@ -81,7 +81,7 @@ export class HandDetector {
       const boxes = prediction.box.dataSync();
       const startPoint = boxes.slice(0, 2);
       const endPoint = boxes.slice(2, 4);
-      const palmLandmarks = prediction.palmLandmarks.arraySync();
+      const palmLandmarks = await prediction.palmLandmarks.array();
       tf.dispose(prediction.box);
       tf.dispose(prediction.palmLandmarks);
       hands.push(box.scaleBoxCoordinates({ startPoint, endPoint, palmLandmarks, confidence: prediction.confidence }, [inputWidth / this.inputSize, inputHeight / this.inputSize]));
diff --git a/src/handpose/handpipeline.ts b/src/handpose/handpipeline.ts
index 5264d56a..511733f3 100644
--- a/src/handpose/handpipeline.ts
+++ b/src/handpose/handpipeline.ts
@@ -122,7 +122,7 @@ export class HandPipeline {
         tf.dispose(confidenceT);
         if (confidence >= config.hand.minConfidence) {
           const keypointsReshaped = tf.reshape(keypoints, [-1, 3]);
-          const rawCoords = keypointsReshaped.arraySync();
+          const rawCoords = await keypointsReshaped.array();
           tf.dispose(keypoints);
           tf.dispose(keypointsReshaped);
           const coords = this.transformRawCoords(rawCoords, newBox, angle, rotationMatrix);
diff --git a/src/movenet/movenet.ts b/src/movenet/movenet.ts
index eb4f1cb6..0db93490 100644
--- a/src/movenet/movenet.ts
+++ b/src/movenet/movenet.ts
@@ -50,7 +50,7 @@ export async function predict(image: Tensor, config: Config): Promise<Body[]> {
 
     if (resT) {
       keypoints.length = 0;
-      const res = resT.arraySync();
+      const res = await resT.array();
       tf.dispose(resT);
       const kpt = res[0][0];
       for (let id = 0; id < kpt.length; id++) {
diff --git a/src/object/centernet.ts b/src/object/centernet.ts
index 2af54dbd..4942d13a 100644
--- a/src/object/centernet.ts
+++ b/src/object/centernet.ts
@@ -28,15 +28,15 @@ export async function load(config: Config): Promise<GraphModel> {
 async function process(res: Tensor, inputSize, outputShape, config: Config) {
   if (!res) return [];
   const results: Array<Item> = [];
-  const detections = res.arraySync();
+  const detections = await res.array();
   const squeezeT = tf.squeeze(res);
   tf.dispose(res);
   const arr = tf.split(squeezeT, 6, 1); // x1, y1, x2, y2, score, class
   tf.dispose(squeezeT);
   const stackT = tf.stack([arr[1], arr[0], arr[3], arr[2]], 1); // reorder dims as tf.nms expects y, x
-  const boxesT = stackT.squeeze();
-  const scoresT = arr[4].squeeze();
-  const classesT = arr[5].squeeze();
+  const boxesT = tf.squeeze(stackT);
+  const scoresT = tf.squeeze(arr[4]);
+  const classesT = tf.squeeze(arr[5]);
   arr.forEach((t) => tf.dispose(t));
   const nmsT = await tf.image.nonMaxSuppressionAsync(boxesT, scoresT, config.object.maxDetected, config.object.iouThreshold, config.object.minConfidence);
   tf.dispose(boxesT);
diff --git a/src/object/nanodet.ts b/src/object/nanodet.ts
index 5219f4ee..11b3800c 100644
--- a/src/object/nanodet.ts
+++ b/src/object/nanodet.ts
@@ -32,14 +32,14 @@ async function process(res, inputSize, outputShape, config) {
   let results: Array<Item> = [];
   for (const strideSize of [1, 2, 4]) { // try each stride size as it detects large/medium/small objects
     // find scores, boxes, classes
-    tf.tidy(() => { // wrap in tidy to automatically deallocate temp tensors
+    tf.tidy(async () => { // wrap in tidy to automatically deallocate temp tensors
       const baseSize = strideSize * 13; // 13x13=169, 26x26=676, 52x52=2704
       // find boxes and scores output depending on stride
       const scoresT = res.find((a) => (a.shape[1] === (baseSize ** 2) && a.shape[2] === labels.length))?.squeeze();
       const featuresT = res.find((a) => (a.shape[1] === (baseSize ** 2) && a.shape[2] < labels.length))?.squeeze();
       const boxesMax = featuresT.reshape([-1, 4, featuresT.shape[1] / 4]); // reshape [output] to [4, output / 4] where number is number of different features inside each stride
-      const boxIdx = boxesMax.argMax(2).arraySync(); // what we need is indexes of features with highest scores, not values itself
-      const scores = scoresT.arraySync(); // optionally use exponential scores or just as-is
+      const boxIdx = await boxesMax.argMax(2).array(); // what we need is indexes of features with highest scores, not values itself
+      const scores = await scoresT.array(); // optionally use exponential scores or just as-is
       for (let i = 0; i < scoresT.shape[0]; i++) { // total strides (x * y matrix)
         for (let j = 0; j < scoresT.shape[1]; j++) { // one score for each class
           const score = scores[i][j]; // get score for current position
diff --git a/src/result.ts b/src/result.ts
index 11babac2..e8806be7 100644
--- a/src/result.ts
+++ b/src/result.ts
@@ -53,8 +53,7 @@ export interface Face {
     matrix: [number, number, number, number, number, number, number, number, number],
     gaze: { bearing: number, strength: number },
   }
-  image?: Tensor;
-  tensor: Tensor,
+  tensor?: Tensor,
 }
 
 /** Body results
diff --git a/tfjs/tf-browser.ts b/tfjs/tf-browser.ts
index 6db3d96e..b21c1eb1 100644
--- a/tfjs/tf-browser.ts
+++ b/tfjs/tf-browser.ts
@@ -3,7 +3,6 @@
  * @external
  */
 
-// import from src
 // get versions of all packages
 import { version as tfjsVersion } from '@tensorflow/tfjs/package.json';
 import { version as tfjsCoreVersion } from '@tensorflow/tfjs-core/package.json';
@@ -14,7 +13,7 @@ import { version as tfjsBackendCPUVersion } from '@tensorflow/tfjs-backend-cpu/p
 import { version as tfjsBackendWebGLVersion } from '@tensorflow/tfjs-backend-webgl/package.json';
 import { version as tfjsBackendWASMVersion } from '@tensorflow/tfjs-backend-wasm/package.json';
 
-// export all
+// export all from sources
 // requires treeShaking:ignore-annotations due to tfjs misconfiguration
 /*
 export * from '@tensorflow/tfjs-core/src/index';
@@ -26,7 +25,7 @@ export * from '@tensorflow/tfjs-backend-webgl/src/index';
 export * from '@tensorflow/tfjs-backend-wasm/src/index';
 */
 
-// export all
+// export all from build
 export * from '@tensorflow/tfjs-core/dist/index.js';
 export * from '@tensorflow/tfjs-layers/dist/index.js';
 export * from '@tensorflow/tfjs-converter/dist/index.js';
@@ -34,6 +33,7 @@ export * as data from '@tensorflow/tfjs-data/dist/index.js';
 export * from '@tensorflow/tfjs-backend-cpu/dist/index.js';
 export * from '@tensorflow/tfjs-backend-webgl/dist/index.js';
 export * from '@tensorflow/tfjs-backend-wasm/dist/index.js';
+// export * from '@tensorflow/tfjs-backend-webgpu/dist/index.js'; // experimental
 
 // export versions
 export const version = {
@@ -46,4 +46,3 @@ export const version = {
   'tfjs-backend-webgl': tfjsBackendWebGLVersion,
   'tfjs-backend-wasm': tfjsBackendWASMVersion,
 };
-// export const version = {};
diff --git a/wiki b/wiki
index 2135debf..bdc4077a 160000
--- a/wiki
+++ b/wiki
@@ -1 +1 @@
-Subproject commit 2135debf198b5b0ecb670896bef837cbb45fe32e
+Subproject commit bdc4077a3df07abdf4a2d5b2d2beadf2e573e8d8