基于TensorFlow.js与Web Worker的智能证件照生成方案

功能简介

本文基于TensorFlow.js与Web Worker实现了常用的“证件照”功能，可以对照片实现抠图并替换背景。值得一提的是，正常抠图的操作应该由后端进行，这里只是主要演示该功能实现步骤，并不建议该功能由前端全权处理。
限于个人技术能力有限，当前功能实现的并不怎么良好，抠图不够精细且缺少对图片处理后的画质修复等操作，这些还请诸位大佬见谅了。

效果演示

原图

## 效果图

功能亮点

• 智能人像分割：基于BodyPix模型实现精准人像抠图
• 实时背景替换：支持动态颜色选择和边缘优化算法
• 多尺寸适配：预设常用证件照尺寸+自定义毫米级精度
• 高性能处理：Web Worker独立线程保障主线程流畅性
• 模型加载优化：按需加载MobileNetV1量化模型
• 边缘平滑算法：卷积核模糊处理提升证件照专业度

主要逻辑详解

加载模型

// 初始化模型
async function loadModel() {try {console.log('开始加载模型...');if (!bodyPixModel) {bodyPixModel = await bodyPix.load({architecture: 'MobileNetV1',outputStride: 16,multiplier: 0.75,quantBytes: 2});console.log('模型加载成功');}return bodyPixModel;} catch (error) {console.error('模型加载失败:', error);throw error;}
}

该方法的主要作用便是加载bodyPixModel模型，这里用到的模型为MobileNetV1。关于bodyPix模型下load方法的各种参数可以自行搜索一下官方文档查看。

人像分割核心流程

    // 使用 BodyPix 进行人像分割console.log('开始人像分割...');const segmentation = await model.segmentPerson(imgDataForSegmentation, {flipHorizontal: false,internalResolution: 'medium',segmentationThreshold: config.segmentationThreshold || 0.7});console.log('人像分割完成');// 创建输出 Canvasconst outputCanvas = new OffscreenCanvas(img.width, img.height);const outputCtx = outputCanvas.getContext('2d');// 绘制原始图片outputCtx.drawImage(img, 0, 0);// 应用背景色const backgroundColor = hexToRgb(config.bgColor);const outputImageData = outputCtx.getImageData(0, 0, img.width, img.height);const pixelData = outputImageData.data;// 应用分割结果for (let i = 0; i < segmentation.data.length; i++) {const n = i * 4;if (segmentation.data[i] === 0) { // 背景部分pixelData[n] = backgroundColor.r;pixelData[n + 1] = backgroundColor.g;pixelData[n + 2] = backgroundColor.b;pixelData[n + 3] = 255;}}outputCtx.putImageData(outputImageData, 0, 0);

这里的主要逻辑是分割图像及应用选择的背景色。

边缘平滑算法

// 边缘平滑处理
async function smoothEdges(ctx, width, height) {const imageData = ctx.getImageData(0, 0, width, height);const data = imageData.data;const kernel = [[0.075, 0.124, 0.075],[0.124, 0.204, 0.124],[0.075, 0.124, 0.075]];const tempData = new Uint8ClampedArray(data);for (let y = 1; y < height - 1; y++) {for (let x = 1; x < width - 1; x++) {const idx = (y * width + x) * 4;if (isEdgePixel(data, idx, width)) {let r = 0, g = 0, b = 0, a = 0;for (let ky = -1; ky <= 1; ky++) {for (let kx = -1; kx <= 1; kx++) {const offset = ((y + ky) * width + (x + kx)) * 4;const weight = kernel[ky + 1][kx + 1];r += tempData[offset] * weight;g += tempData[offset + 1] * weight;b += tempData[offset + 2] * weight;a += tempData[offset + 3] * weight;}}data[idx] = r;data[idx + 1] = g;data[idx + 2] = b;data[idx + 3] = a;}}}ctx.putImageData(imageData, 0, 0);
}

这里使用3*3卷积核对边缘像素进行了加权平均处理，从而消除锯齿效果。这里用到的isEdgePixel（）方法目的是判断一个像素是否为图像的边缘像素，方法是通过比较该像素与其相邻像素的alpha通道值（也就是透明度）。

function isEdgePixel(data, idx, width) {const alpha = data[idx + 3];const leftAlpha = data[idx - 4 + 3];const rightAlpha = data[idx + 4 + 3];const topAlpha = data[idx - width * 4 + 3];const bottomAlpha = data[idx + width * 4 + 3];return (alpha !== leftAlpha || alpha !== rightAlpha || alpha !== topAlpha || alpha !== bottomAlpha);
}

完整代码

IDPhoto.vue

<template><div class="id-photo-container"><!-- 左侧工具栏 --><div class="tools-panel"><el-form :model="photoConfig" label-position="top"><!-- 预设尺寸选择 --><el-form-item label="证件照尺寸"><el-select v-model="photoConfig.selectedSize" placeholder="选择尺寸"><el-optionv-for="size in presetSizes":key="size.value":label="size.label":value="size.value"/></el-select></el-form-item><!-- 自定义尺寸输入 --> <el-form-item label="自定义尺寸(mm)"><div class="custom-size"><el-input-number v-model="photoConfig.customWidth" :min="20" :max="1000"placeholder="宽度"/><span class="separator">×</span><el-input-number v-model="photoConfig.customHeight" :min="20" :max="1000"placeholder="高度"/></div></el-form-item><!-- 背景颜色选择 --><el-form-item label="背景颜色"><el-color-picker v-model="photoConfig.bgColor" /></el-form-item><!-- 操作按钮 --><div class="action-buttons"><el-button type="primary" @click="uploadImage">上传图片</el-button><el-button type="success" :disabled="!hasImage"@click="downloadPhoto">下载证件照</el-button></div></el-form></div><!-- 右侧预览区域 --><div class="preview-panel"><div class="preview-area":style="{ backgroundColor: photoConfig.bgColor }"><img v-if="previewUrl":src="previewUrl"ref="previewImage"@load="handleImageLoad"/><div v-else class="placeholder">请上传图片</div></div></div><!-- 隐藏的文件输入框 --><inputtype="file"ref="fileInput"accept="image/*"style="display: none"@change="handleFileChange"/><el-loading v-model:visible="loading"text="处理中..."background="rgba(255, 255, 255, 0.8)"/></div>
</template><script setup>
import { ref, reactive, onMounted, onUnmounted, watch } from 'vue'
import { ElMessage } from 'element-plus'// 预设尺寸选项
const presetSizes = [{ label: '一寸照片 (25×35mm)', value: '25x35' },{ label: '二寸照片 (35×49mm)', value: '35x49' },{ label: '小二寸 (35×45mm)', value: '35x45' },{ label: '大二寸 (35×53mm)', value: '35x53' }
]// 照片配置
const photoConfig = reactive({selectedSize: '35x45',customWidth: 35,customHeight: 45,bgColor: '#FFFFFF',modelQuality: 'medium', // 可选: 'low', 'medium', 'high'segmentationThreshold: 0.7, // 分割阈值，可调整精度edgeBlur: 3 // 边缘模糊半径
})// 组件引用
const fileInput = ref(null)
const previewImage = ref(null)// 状态变量
const previewUrl = ref('')
const hasImage = ref(false)// 图片处理 Worker
let imageWorker = null// 添加加载状态
const loading = ref(false)// 初始化 Worker
onMounted(() => {try {// 使用 ?worker 查询参数来告诉 Vite 这是一个 worker 文件imageWorker = new Worker(new URL('../../workers/idphoto.worker.js?worker', import.meta.url),{ type: 'module' })imageWorker.onmessage = (e) => {console.log('收到Worker响应:', e.data)if (e.data.status === 'success') {const blobUrl = URL.createObjectURL(e.data.result)previewUrl.value = blobUrlloading.value = false // 确保加载状态被重置} else {console.error('Worker处理失败:', e.data.error)ElMessage.error(`处理图片时出错: ${e.data.error}`)loading.value = false}}imageWorker.onerror = (error) => {console.error('Worker错误:', error)ElMessage.error('图片处理服务初始化失败')loading.value = false}} catch (error) {console.error('创建Worker失败:', error)ElMessage.error('初始化图片处理服务失败')loading.value = false}
})// 清理 Worker
onUnmounted(() => {if (imageWorker) {imageWorker.terminate()}
})// 上传图片
const uploadImage = () => {fileInput.value.click()
}// 处理文件选择
const handleFileChange = async (event) => {const file = event.target.files[0]if (!file) returnif (!file.type.startsWith('image/')) {ElMessage.error('请上传图片文件')return}if (file.size > 10 * 1024 * 1024) { // 10MB 限制ElMessage.error('图片大小不能超过10MB')return}loading.value = trueElMessage.info('正在处理图片，首次使用可能需要加载模型...')const reader = new FileReader()reader.onload = (e) => {const img = new Image()img.onload = () => {console.log('图片加载成功，尺寸:', img.width, 'x', img.height)try {imageWorker.postMessage({imageData: e.target.result,config: {width: img.width,height: img.height,bgColor: photoConfig.bgColor,segmentationThreshold: photoConfig.segmentationThreshold,modelQuality: photoConfig.modelQuality}})} catch (error) {loading.value = falseconsole.error('发送数据到Worker时出错:', error)ElMessage.error('处理图片时出错')}}img.onerror = (error) => {loading.value = falseconsole.error('图片加载失败:', error)ElMessage.error('图片加载失败')}img.src = e.target.resulthasImage.value = true}reader.onerror = (error) => {loading.value = falseconsole.error('读取文件失败:', error)ElMessage.error('读取文件失败')}reader.readAsDataURL(file)
}// 处理图片加载
const handleImageLoad = () => {// 这里可以添加图片加载后的处理逻辑
}// 下载证件照
const downloadPhoto = async () => {if (!hasImage.value) returntry {const response = await fetch(previewUrl.value)const blob = await response.blob()const link = document.createElement('a')link.download = '证件照.png'link.href = URL.createObjectURL(blob)link.click()ElMessage.success('下载成功')} catch (error) {ElMessage.error('下载图片时出错')console.error(error)}
}// 添加背景色变化监听
watch(() => photoConfig.bgColor, (newColor) => {if (hasImage.value && previewUrl.value) {const img = new Image()img.onload = () => {imageWorker.postMessage({imageData: previewUrl.value,config: {width: img.width,height: img.height,bgColor: newColor}})}img.src = previewUrl.value}
})
</script><style scoped>
.id-photo-container {display: flex;gap: 20px;padding: 20px;height: 100%;
}.tools-panel {width: 300px;padding: 20px;background: #f5f7fa;border-radius: 8px;
}.preview-panel {flex: 1;display: flex;justify-content: center;align-items: center;background: #f5f7fa;border-radius: 8px;overflow: hidden;
}.preview-area {width: 80%;height: 80%;display: flex;justify-content: center;align-items: center;background: #fff;border-radius: 4px;box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
}.preview-area img {max-width: 100%;max-height: 100%;object-fit: contain;
}.placeholder {color: #909399;font-size: 16px;
}.custom-size {display: flex;align-items: center;gap: 10px;
}.separator {color: #909399;
}.action-buttons {display: flex;gap: 10px;margin-top: 20px;
}
</style>

idphoto.workder.js

import * as tf from '@tensorflow/tfjs'
import * as bodyPix from '@tensorflow-models/body-pix'let bodyPixModel = null;// 初始化模型
async function loadModel() {try {console.log('开始加载模型...');if (!bodyPixModel) {bodyPixModel = await bodyPix.load({architecture: 'MobileNetV1',outputStride: 16,multiplier: 0.75,quantBytes: 2});console.log('模型加载成功');}return bodyPixModel;} catch (error) {console.error('模型加载失败:', error);throw error;}
}// 处理图片的 Worker
self.onmessage = async function(e) {console.log('Worker 收到消息:', e.data);const { imageData, config } = e.data;try {if (!imageData || !config) {throw new Error('缺少必要的参数')}// 加载模型const model = await loadModel();console.log('模型准备就绪');// 创建图片元素const img = await createImageBitmap(await fetch(imageData).then(r => r.blob()));// 创建离屏 Canvasconst canvas = new OffscreenCanvas(img.width, img.height);const ctx = canvas.getContext('2d');if (!ctx) {throw new Error('无法创建Canvas上下文')}// 绘制原始图片ctx.drawImage(img, 0, 0);console.log('图片绘制完成');// 获取图片数据const imgDataForSegmentation = ctx.getImageData(0, 0, img.width, img.height);// 使用 BodyPix 进行人像分割console.log('开始人像分割...');const segmentation = await model.segmentPerson(imgDataForSegmentation, {flipHorizontal: false,internalResolution: 'medium',segmentationThreshold: config.segmentationThreshold || 0.7});console.log('人像分割完成');// 创建输出 Canvasconst outputCanvas = new OffscreenCanvas(img.width, img.height);const outputCtx = outputCanvas.getContext('2d');// 绘制原始图片outputCtx.drawImage(img, 0, 0);// 应用背景色const backgroundColor = hexToRgb(config.bgColor);const outputImageData = outputCtx.getImageData(0, 0, img.width, img.height);const pixelData = outputImageData.data;// 应用分割结果for (let i = 0; i < segmentation.data.length; i++) {const n = i * 4;if (segmentation.data[i] === 0) { // 背景部分pixelData[n] = backgroundColor.r;pixelData[n + 1] = backgroundColor.g;pixelData[n + 2] = backgroundColor.b;pixelData[n + 3] = 255;}}outputCtx.putImageData(outputImageData, 0, 0);// 优化边缘await smoothEdges(outputCtx, img.width, img.height);// 转换为 Blobconst resultBlob = await outputCanvas.convertToBlob({type: 'image/png'});console.log('处理完成，发送结果');self.postMessage({status: 'success',result: resultBlob});} catch (error) {console.error('Worker处理错误:', error);self.postMessage({status: 'error',error: error.message || '处理图片时发生未知错误'});}
};// 边缘平滑处理
async function smoothEdges(ctx, width, height) {const imageData = ctx.getImageData(0, 0, width, height);const data = imageData.data;const kernel = [[0.075, 0.124, 0.075],[0.124, 0.204, 0.124],[0.075, 0.124, 0.075]];const tempData = new Uint8ClampedArray(data);for (let y = 1; y < height - 1; y++) {for (let x = 1; x < width - 1; x++) {const idx = (y * width + x) * 4;if (isEdgePixel(data, idx, width)) {let r = 0, g = 0, b = 0, a = 0;for (let ky = -1; ky <= 1; ky++) {for (let kx = -1; kx <= 1; kx++) {const offset = ((y + ky) * width + (x + kx)) * 4;const weight = kernel[ky + 1][kx + 1];r += tempData[offset] * weight;g += tempData[offset + 1] * weight;b += tempData[offset + 2] * weight;a += tempData[offset + 3] * weight;}}data[idx] = r;data[idx + 1] = g;data[idx + 2] = b;data[idx + 3] = a;}}}ctx.putImageData(imageData, 0, 0);
}function isEdgePixel(data, idx, width) {const alpha = data[idx + 3];const leftAlpha = data[idx - 4 + 3];const rightAlpha = data[idx + 4 + 3];const topAlpha = data[idx - width * 4 + 3];const bottomAlpha = data[idx + width * 4 + 3];return (alpha !== leftAlpha || alpha !== rightAlpha || alpha !== topAlpha || alpha !== bottomAlpha);
}function hexToRgb(hex) {const result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);return result ? {r: parseInt(result[1], 16),g: parseInt(result[2], 16),b: parseInt(result[3], 16)} : null;
} 

注

以上便是证件照功能的全部逻辑，其实我这里写的相当简陋且具有很大的扩展空间。各位大佬如果有精力，可以在这个基础上 增加服装替换、美颜等功能，以及可以进一步优化UI界面（我这里样式写的不是特别好）。
总之，感谢阅读了，愿你我都能在技术之路上更进一步！