mnist : add web page for the MNIST example (#190)

The web page is using WASM for model inference. Users can draw digits on an HTML canvas and load random digits from the MNIST dataset.
ggerganov · May 24, 2023 · 42bfaaf · 42bfaaf
1 parent d30ef19
commit 42bfaaf
Show file tree

Hide file tree

Showing 2 changed files with 161 additions and 0 deletions.
diff --git a/examples/mnist/main.cpp b/examples/mnist/main.cpp
@@ -208,6 +208,41 @@ int mnist_eval(
  return prediction;
 }
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int wasm_eval(uint8_t *digitPtr)
+{
+ mnist_model model;
+ if (!mnist_model_load("models/mnist/ggml-model-f32.bin", model)) {
+ fprintf(stderr, "error loading model\n");
+ return -1;
+ }
+ std::vector<float> digit(digitPtr, digitPtr + 784);
+ int result = mnist_eval(model, 1, digit);
+ ggml_free(model.ctx);
+ return result;
+}
+
+int wasm_random_digit(char *digitPtr)
+{
+ auto fin = std::ifstream("models/mnist/t10k-images.idx3-ubyte", std::ios::binary);
+ if (!fin) {
+ fprintf(stderr, "failed to open digits file\n");
+ return 0;
+ }
+ srand(time(NULL));
+ // Seek to a random digit: 16-byte header + 28*28 * (random 0 - 10000)
+ fin.seekg(16 + 784 * (rand() % 10000));
+ fin.read(digitPtr, 784);
+ return 1;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
 int main(int argc, char ** argv) {
  srand(time(NULL));
  ggml_time_init();

diff --git a/examples/mnist/web/index.html b/examples/mnist/web/index.html
@@ -0,0 +1,126 @@
+<!DOCTYPE html>
+<html>
+<head>
+ <meta charset="utf-8">
+ <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
+ <title>MNIST with GGML</title>
+ <script src="mnist.js"></script>
+</head>
+<body>
+ <h2>MNIST digit recognizer with GGML</h2>
+ <p>Draw a single digit on the canvas below:</p>
+ <canvas id="ggCanvas" width="364" height="364" style="border:2px solid #d3d3d3;">
+ Your browser does not support the HTML canvas tag.
+ </canvas>
+ <div>
+ <button id="clear" onclick="onClear()">Clear</button>
+ <button id="random" onclick="onRandom()">Random</button>
+ </div>
+ <div>
+ <p id="prediction"></p>
+ </div>
+ <script>
+"use strict";
+const DIGIT_SIZE = 28; // digits are 28x28 pixels
+var canvas = document.getElementById("ggCanvas");
+var ctx = canvas.getContext("2d");
+var digit = new Array(DIGIT_SIZE*DIGIT_SIZE).fill(0);
+var dragging = false;
+
+function onClear(event) {
+ ctx.clearRect(0, 0, canvas.width, canvas.height);
+ digit.fill(0);
+ document.getElementById("prediction").innerHTML = "";
+}
+
+function onRandom(event) {
+ onClear();
+ var buf = Module._malloc(digit.length);
+ if (buf == 0) {
+ console.log("failed to allocate memory");
+ return;
+ }
+ let ret = Module.ccall('wasm_random_digit', null, ['number'], [buf]);
+ let digitBytes = new Uint8Array(Module.HEAPU8.buffer, buf, digit.length);
+ for (let i = 0; i < digit.length; i++) {
+ digit[i] = digitBytes[i];
+ let x = i % DIGIT_SIZE;
+ let y = Math.floor(i / DIGIT_SIZE);
+ setPixel(x, y, digit[i]);
+ }
+ Module._free(buf);
+ onMouseUp();
+}
+
+// Get the position of the mouse relative to the canvas
+function getMousePos(event) {
+ if (event.touches !== undefined && event.touches.length > 0) {
+ event = event.touches[0];
+ }
+ var rect = canvas.getBoundingClientRect();
+ return [Math.floor(event.clientX) - rect.left, Math.floor(event.clientY) - rect.top];
+}
+
+function setPixel(x, y, val) {
+ digit[y * DIGIT_SIZE + x] = val;
+ let canvasX = x * 13;
+ let canvasY = y * 13;
+ let color = 255 - val;
+ ctx.fillStyle = "#" + color.toString(16) + color.toString(16) + color.toString(16);
+ ctx.fillRect(canvasX, canvasY, 13, 13);
+}
+
+function onMouseDown(e) {
+ dragging = true;
+ let [mouseX, mouseY] = getMousePos(e);
+ setPixel(Math.floor(mouseX / 13), Math.floor(mouseY / 13), 255);
+}
+
+function onMouseUp(e) {
+ dragging = false;
+ var buf = Module._malloc(digit.length);
+ if (buf == 0) {
+ console.log("failed to allocate memory");
+ return;
+ }
+ Module.HEAPU8.set(digit, buf);
+ let prediction = Module.ccall('wasm_eval', null, ['number'], [buf]);
+ Module._free(buf);
+ if (prediction >= 0) {
+ document.getElementById("prediction").innerHTML = "Predicted digit is <b>" + prediction + "</b>";
+ }
+}
+function onMouseMove(e) {
+ if (dragging) {
+ let [mouseX, mouseY] = getMousePos(e);
+ setPixel(Math.floor(mouseX / 13), Math.floor(mouseY / 13), 255);
+ }
+}
+
+// Prevent scrolling when touching the canvas
+document.body.addEventListener("touchstart", function (e) {
+if (e.target == canvas) {
+ e.preventDefault();
+}
+}, {passive: false});
+document.body.addEventListener("touchend", function (e) {
+if (e.target == canvas) {
+ e.preventDefault();
+}
+}, {passive: false});
+document.body.addEventListener("touchmove", function (e) {
+if (e.target == canvas) {
+ e.preventDefault();
+}
+}, {passive: false});
+
+// Use the same handlers for mouse and touch events
+canvas.onmousedown = onMouseDown;
+canvas.onmouseup = onMouseUp;
+canvas.onmousemove = onMouseMove;
+canvas.ontouchstart = onMouseDown;
+canvas.ontouchend = onMouseUp;
+canvas.ontouchmove = onMouseMove;
+ </script>
+</body>
+</html>