html调用电脑/手机摄像头拍照上传+百度文字识别

最新推荐文章于 2025-02-20 13:48:59 发布

临渊行

最新推荐文章于 2025-02-20 13:48:59 发布

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分类专栏：这里有个坑文章标签： html拍照上传提取图片文字调用电脑摄像头调用手机摄像头百度文字识别

本文链接：https://blog.youkuaiyun.com/qq_32360995/article/details/108315010

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17 篇文章

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1、需求

利用电脑、手机摄像头对某零件拍照提取上面的文字（电脑我只用chrome测试过）

2、前端

Ps：id='data'的值就是base64，可通过post请求传到后端

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8" %>
<html lang="en">
<head>
    <title>电脑摄像头拍照&文字识别</title>
</head>
<body>
<table border="1px">
    <tr>
        <td>
            <video id="video" width="320px" height="240px" autoplay="autoplay"></video>
        </td>
    </tr>
    <tr>
        <td>
            <canvas id="canvas" width="320px" height="240px"></canvas>
        </td>
    </tr>
    <tr>
        <td>
            <input type="text" value="" id="data" hidden>
            <input type="button" title="开启摄像头" value="开启摄像头" onclick="getMedia()"/>&nbsp;&nbsp;&nbsp;
            <button type="button" id="snap" onclick="takePhoto()">拍照</button>&nbsp;&nbsp;&nbsp;
            <input type="button" title="关闭摄像头" value="关闭摄像头" onclick="closeCamera()"/>
        </td>
    </tr>
</table>
<script>
    //获得video摄像头区域
    var buffer;
    var video = document.getElementById("video");

    function getMedia() {
        navigator.mediaDevices.enumerateDevices()
            .then(function (devices) {
                devices.forEach(function (device) {
                    //打印电脑上的设备类型、设备名称、设备ID
                    console.log(device.kind + ":" + device.label + "  id=" + device.deviceId);
                });
            }).catch(function (err) {
            console.log(err.name + ":" + err.message);
        });

        var constraints = {
            video: {facingMode: {exact: "environment"}},
            audio: false
        };
        /*
        这里介绍新的方法:H5新媒体接口 navigator.mediaDevices.getUserMedia()
        这个方法会提示用户是否允许媒体输入,(媒体输入主要包括相机,视频采集设备,屏幕共享服务,麦克风,A/D转换器等)
        返回的是一个Promise对象。
        如果用户同意使用权限,则会将 MediaStream对象作为resolve()的参数传给then()
        如果用户拒绝使用权限,或者请求的媒体资源不可用,则会将 PermissionDeniedError作为reject()的参数传给catch()
        */
        var promise = navigator.mediaDevices.getUserMedia(constraints);
        promise.then(function (MediaStream) {
            buffer = MediaStream;
            video.srcObject = MediaStream;
            video.play();
        }).catch(function (PermissionDeniedError) {
            console.log(PermissionDeniedError);
        })
    }

    function takePhoto() {
        //获得Canvas对象
        var canvas = document.getElementById("canvas");
        var ctx = canvas.getContext('2d');
        ctx.drawImage(video, 0, 0, 320, 240);
        var str = canvas.toDataURL("image/jpeg");
        document.getElementById("data").value = (str.substr(str.indexOf(",") + 1));
    }

    function closeCamera() {
        buffer && buffer.getTracks()[1].stop();//关闭摄像头
    }
</script>
</body>
</html>

Ps：调用手机摄像头拍照上传，仅部分手机浏览器支持，比如QQ、UC；电脑浏览器可选择磁盘路径下的图片

<input type="file" style="text-align: center" onchange="showPic(event)" accept="image/*"  multiple>

<script>
        var formData;
        var xm;
        var cnt = 0;

        window.onload = function () {
            formData = new FormData();
            cnt = 0;
        };


        //图片压缩
        function photoCompress(file, callback){
            var reader=new FileReader();
            reader.readAsDataURL(file);
            reader.onload=function(){
                var path=this.result;
                canvasDataURL(path, callback)
            }
        }

        function canvasDataURL(path, callback){
            var img = new Image();
            img.src = path;
            img.onload = function(){
                var that = this;
                // 默认按比例压缩
                var w = that.width*0.5;
                var h = that.height*0.5;
                var quality = 0.5;  // 默认图片质量为0.7
                //生成canvas
                var canvas = document.createElement('canvas');
                var ctx = canvas.getContext('2d');
                // 创建属性节点
                var anw = document.createAttribute("width");
                anw.nodeValue = w;
                var anh = document.createAttribute("height");
                anh.nodeValue = h;
                canvas.setAttributeNode(anw);
                canvas.setAttributeNode(anh);
                ctx.drawImage(that, 0, 0, w, h);
                // quality值越小，所绘制出的图像越模糊
                var base64 = canvas.toDataURL('image/jpeg', quality);
                // 回调函数返回base64的值
                callback(base64);
            }
        }

        //图片压缩，并在页面上显示（预览）
        function showPic(e) {
            var files = e.target.files;
            for (var i = 0; i < files.length; i++) {
                photoCompress(files[i],function (base64) {
                    formData.append(xm+cnt, base64.substr(base64.indexOf(",")+1));
                    cnt++;
                });
            }
        }

        function Submit() {
            formData.append("xm", xm);
            formData.append("num", cnt);
            var url="***********";
            $.ajax({
                url : url,
                data :  formData,
                processData : false,
                contentType : false,
                dataType: 'json',
                type : "POST",
                success : function(data){
                    if(data.msg != "") {
                        alert(data.msg);
                    } else {
                        alert("上传成功");
                    }
                    location.reload(true);
                }
            });
        }
    </script>

3、后端（百度文字识别建议去百度智能云查看相关文档以及下载所需SDK）

String pic = request.getParameter("pic");
		String wlh = request.getParameter("wlh");
		Calendar cal = Calendar.getInstance();
		int day = cal.get(Calendar.DATE);
		int month = cal.get(Calendar.MONTH) + 1;
		int year = cal.get(Calendar.YEAR);
        net.sf.json.JSONObject jobj = new net.sf.json.JSONObject();

		String path = "";
		if(System.getProperties().getProperty("os.name").toLowerCase().indexOf("win") != -1) {
			path = "F:\\"+year+"\\"+month+"\\"+day;
		} else {
			path = DomGetServer.getDocBase("/zcjy")+"/"+year+"/"+month+"/"+day;
		}

		createDir(path);
		boolean b = generateImage(pic, path, wlh);
		if(b == false) {
			msg = "图片上传失败";
		} else {
			path = path+"/"+wlh+".jpg";
			OcrUtil ocrUtil = new OcrUtil();
			JSONObject json = ocrUtil.client.handwriting(path, new HashMap<String, String>());
			JSONArray res = json.getJSONArray("words_result");
			for (int i = 0; i < res.length(); i++) {
				JSONObject o = (JSONObject) res.get(i);
				msg += o.get("words");
				if(i != res.length()-1) {
					msg += "/";
				}
			}
		}

public static boolean generateImage(String imgStr,String path,String name) {
        //对字节数组字符串进行Base64解码并生成图片
        if (imgStr == null) {
            return false;
        }

        BASE64Decoder decoder = new BASE64Decoder();
        try {
            byte[] b = decoder.decodeBuffer(imgStr);
            for(int i=0;i<b.length;++i) {
                if(b[i]<0) {
                    b[i]+=256;
                }
            }
            String imgFilePath = path+"/"+name+".jpg";
            OutputStream out = new FileOutputStream(imgFilePath);
            out.write(b);
            out.flush();
            out.close();
            return true;
        } catch (Exception e) {
            System.out.println("===========图片上传异常==========");
            e.printStackTrace();
            System.out.println("===========图片上传异常==========");
            return false;
        }
    }

    /**
     * 递归创建文件夹
     * @param destDirName
     * @return
     */
    public static boolean createDir(String destDirName) {
        File dir = new File(destDirName);
        if (dir.exists()) {
            return false;
        }
        if (dir.mkdirs()) {
            return true;
        } else {
            return false;
        }
    }

import com.baidu.aip.ocr.AipOcr;

/**
 * 百度文字识别
 * @author pxChen
 * @date 2020/8/24
 */
public class OcrUtil {
    //设置APPID/AK/SK
    public static final String APP_ID = "2220****";
    public static final String API_KEY = "XWoPNcxUgjDQTzzI3kq5****";
    public static final String SECRET_KEY = "mRZ0ThKrSAQM4ZGiUGtCYze*********";
    public AipOcr client;

    public OcrUtil() {
        // 初始化一个AipOcr
        client = new AipOcr(APP_ID, API_KEY, SECRET_KEY);

        // 可选：设置网络连接参数
        client.setConnectionTimeoutInMillis(2000);
        client.setSocketTimeoutInMillis(60000);

        // 可选：设置代理服务器地址, http和socket二选一，或者均不设置
        //client.setHttpProxy("proxy_host", proxy_port);  // 设置http代理
        //client.setSocketProxy("proxy_host", proxy_port);  // 设置socket代理

        // 可选：设置log4j日志输出格式，若不设置，则使用默认配置
        // 也可以直接通过jvm启动参数设置此环境变量
        //System.setProperty("aip.log4j.conf", "path/to/your/log4j.properties");
    }
}