ios手機豎屏拍照圖片旋轉90°問題解決方法

手機拍照會給圖片添加一個Orientaion信息(即拍照方向),以下:html

用ios手機拍照,系統會給圖片加上一個方向的屬性, ios相機默認的拍照方向是後攝Home鍵在右爲正,前攝Home鍵在左爲正。前端

 

1表明正常的拍攝角度,ios橫屏下拍攝、安卓機不管橫屏豎屏拍攝,Orientaion的值都爲1;可是ios豎屏拍攝,Orientaion的值爲6,即豎着拍出的照片被添加了一個順時jquery

針旋轉90°的拍照方向,顯示的時候其實就是橫着拍的照片順時針旋轉90°而成。當咱們對拍出來的照片進行處理後,這個拍攝方向Orientaion信息就會丟失,顯示的效果android

天然回到橫屏狀態,看起來像是逆時針旋轉了90°。ios

 

實際上iOS手機豎着拍出的照片與橫着拍出的照片其本質上是同樣的,只不過豎着拍出的照片被添加了一個順時針旋轉90°的拍照方向,因此顯示的時候,就是橫着拍的照web

片順時針旋轉90°而成的,照片旋轉bug的緣由、其實就是當咱們在前端對圖片進行像素處理或者drawInRect等操做以後,照片ajax

的Orientaion信息,即爲拍照方向信息被刪除了,因此iOS手機豎着拍的照片又回到了橫着的狀態,看起來也就是逆時針旋轉了90°!canvas

 

html服務器

<!doctype html>app

<html lang="en">

<head>

    <meta charset="UTF-8">

    <meta name="viewport"

          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">

    <meta http-equiv="X-UA-Compatible" content="ie=edge">

    <title>前端解決ios手機豎拍上傳圖片旋轉90° 完美適配:Android/ios/Windows</title>

    <script src="js/jquery-1.11.3.min.js"></script>

    <script src="js/exif.js"></script>

    <script src="js/uploadImage.js"></script>

    <script src="js/tech.js"></script>

</head>

<body>

<div class="featfile">

    <div class="featimage featupfile phoneclick" id="imgcontainer">

        <img src="" class="fileimg" id="fileimg">

        <!--canvas 爲後文引用-->

        <canvas id="Drawborder"></canvas>

    </div>

    <!--   multiple="multiple" 是爲了input能直接支持 Formdata 上傳圖片到後臺 後文有述 -->

    <input type=file name="image" multiple="multiple" class="imgfilebtn" accept="image/jpeg,image/png,image/gif,image/jpg" onchange="selectFileImage(this)">

</div>

</body>

</html>

 

js

function selectFileImage(fileObj) {

    var file = fileObj.files['0'];

    var Orientation = null;

    $('.loading_bg').fadeIn();

    if (file) {

        console.log("正在上傳,請稍後...");

        var rFilter = /^(image\/jpeg|image\/png)$/i; // 檢查圖片格式

        if (!rFilter.test(file.type)) {

            //showMyTips("請選擇jpeg、png格式的圖片", false);

            return;

        }

        // var URL = URL || webkitURL;

        //獲取照片方向角屬性,用戶旋轉控制

        EXIF.getData(file, function() {

            // alert(EXIF.pretty(this));

            EXIF.getAllTags(this);

            //alert(EXIF.getTag(this, 'Orientation'));

            Orientation = EXIF.getTag(this, 'Orientation');

            //return;

        });

 

        var oReader = new FileReader();

        oReader.onload = function(e) {

            //var blob = URL.createObjectURL(file);

            //_compress(blob, file, basePath);

            var image = new Image();

            image.src = e.target.result;

            image.onload = function() {

                var expectWidth = this.naturalWidth;

                var expectHeight = this.naturalHeight;

 

                if (this.naturalWidth > this.naturalHeight && this.naturalWidth > 800) {

                    expectWidth = 800;

                    expectHeight = expectWidth * this.naturalHeight / this.naturalWidth;

                } else if (this.naturalHeight > this.naturalWidth && this.naturalHeight > 1200) {

                    expectHeight = 1200;

                    expectWidth = expectHeight * this.naturalWidth / this.naturalHeight;

                }

                var canvas = document.createElement("canvas");

                var ctx = canvas.getContext("2d");

                canvas.width = expectWidth;

                canvas.height = expectHeight;

                ctx.drawImage(this, 0, 0, expectWidth, expectHeight);

                var u = navigator.userAgent;

                //修復ios

                if (u.match(/iphone/i)) {

                    console.log('iphone');

                    //若是方向角不爲1,都須要進行旋轉 added by lzk

                    if(Orientation != "" && Orientation != 1){

                        console.log('旋轉處理');

                        switch(Orientation){

                            case 6://須要順時針(向左)90度旋轉

                                console.log('須要順時針(向左)90度旋轉');

                                rotateImg(this,'left',canvas);

                                break;

                            case 8://須要逆時針(向右)90度旋轉

                                console.log('須要逆時針(向右)90度旋轉');

                                rotateImg(this,'right',canvas);

                                break;

                            case 3://須要180度旋轉

                                console.log('須要180度旋轉');

                                rotateImg(this,'right',canvas);//轉兩次

                                rotateImg(this,'right',canvas);

                                break;

                        }

                    }

                    //base64 在外定義爲全局變量

                    //下面base64爲獲得旋轉後的base64圖片

                    base64 = canvas.toDataURL("image/jpeg", 0.8);

                    var type = 'jpeg';

                    var fixtype = function (type) {

                        type = type.toLocaleLowerCase().replace(/jpg/i, 'jpeg');

                        var r = type.match(/png|jpeg|bmp|gif/)[0];

                        return 'image/' + r;

                    };

                    base64 = base64.replace(fixtype(type), 'image/jpeg');

                    // saveFile(base64, '111')  此處是若是想要保存當前圖片到本地的話;

 

                    //這裏是把已經旋轉過的圖片路徑賦值到img中

                    $(".fileimg").attr("src", base64);

                }

                else if (u.indexOf('Android') > -1 || u.indexOf('Adr') > -1) {// android能夠直接不變

                    $(".fileimg").attr("src", e.target.result);

                    //若是安卓收到ios拍攝的照片,能夠按PC端方式判斷

                }

                else{

                    //修復PC端上上傳ios拍出來的圖片

                    if(Orientation != "" && Orientation != 1){

                        //alert('旋轉處理');

                        switch(Orientation){

                            case 6://須要順時針(向左)90度旋轉

                                console.log('須要順時針(向左)90度旋轉');

                                rotateImg(this,'left',canvas);

                                break;

                            case 8://須要逆時針(向右)90度旋轉

                                console.log('須要逆時針(向右)90度旋轉');

                                rotateImg(this,'right',canvas);

                                break;

                            case 3://須要180度旋轉

                                console.log('須要180度旋轉');

                                rotateImg(this,'right',canvas);//轉兩次

                                rotateImg(this,'right',canvas);

                                break;

                        }

                    }

                    base64 = canvas.toDataURL("image/jpeg", 0.8);

                    var type = 'jpeg';

                    var fixtype = function (type) {

                        type = type.toLocaleLowerCase().replace(/jpg/i, 'jpeg');

                        var r = type.match(/png|jpeg|bmp|gif/)[0];

                        return 'image/' + r;

                    };

                    base64 = base64.replace(fixtype(type), 'image/jpeg');

                    // saveFile(base64, '111');

                    $(".fileimg").attr("src", base64);

                }

 

            };

        };

        oReader.readAsDataURL(file);

    }

}

 

 

//將圖片保存到本地

var saveFile = function (data, filename) {

    var link = document.createElement('a');

    link.href = data;

    link.download = filename;

    var event = document.createEvent('MouseEvents');

    event.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);

    link.dispatchEvent(event);

}

 

 

//對圖片旋轉處理 added by lzk

function rotateImg(img, direction,canvas) {

    //alert(img);

    //最小與最大旋轉方向,圖片旋轉4次後回到原方向

    var min_step = 0;

    var max_step = 3;

    //var img = document.getElementById(pid);

    if (img == null)return;

    //img的高度和寬度不能在img元素隱藏後獲取,不然會出錯

    var height = img.height;

    var width = img.width;

    //var step = img.getAttribute('step');

    var step = 2;

    if (step == null) {

        step = min_step;

    }

    if (direction == 'right') {

        step++;

        //旋轉到原位置,即超過最大值

        step > max_step && (step = min_step);

    } else {

        step--;

        step < min_step && (step = max_step);

    }

    //旋轉角度以弧度值爲參數

    var degree = step * 90 * Math.PI / 180;

    var ctx = canvas.getContext('2d');

    switch (step) {

        case 0:

            canvas.width = width;

            canvas.height = height;

            ctx.drawImage(img, 0, 0);

            break;

        case 1:

            canvas.width = height;

            canvas.height = width;

            ctx.rotate(degree);

            ctx.drawImage(img, 0, -height);

            break;

        case 2:

            canvas.width = width;

            canvas.height = height;

            ctx.rotate(degree);

            ctx.drawImage(img, -width, -height);

            break;

        case 3:

            canvas.width = height;

            canvas.height = width;

            ctx.rotate(degree);

            ctx.drawImage(img, -width, 0);

            break;

    }

}

 

下面講述一下如何用ajax傳輸base64圖片,不須要表單,直接使用input就能夠完成

 

上文html中有述, 在input中添加multiple="multiple"屬性便可

 

//此函數是爲了轉化base64的值,用於傳給後臺

function convertBase64Url(urlData){

 

     //獲取canvas中的圖片信息

         //window.atob方法將其中的base64格式的圖片轉換成二進制字符串;若將轉換後的值直接賦值給Blob會報錯,需Uint8Array轉換:最後建立Blob對象;

         var _data = window.atob(data.split(",")[1]);

 

         //若是不用ArrayBuffer,發送給服務器的圖片格式是[object Uint8Array],上傳失敗...

         var buffer = new ArrayBuffer(_data.length);

         var _buffer = new Uint8Array(buffer);

         for(var i = 0; i < _data.length; i++) {

                   _buffer[i] = _data.charCodeAt(i);

         }

 

         var blob;

var Builder = window.BlobBuilder || window.WebKitBlobBuilder || window.MozBlobBuilder || window.MSBlobBuilder;;

 

         if(Builder) {

                   var builder = new Builder();

                   builder.append(_buffer);

                   blob = builder.getBlob('image/jpeg');

         } else {

                   blob = new window.Blob([_buffer], {

                            type: 'image/jpeg'

                   });

         }

         return blob;}

 

//到這裏就能實現與後臺的交互了

var base64 = null;

$('.button').click(function(){

    var formDate = new FormData();

    formDate.append('image', convertBase64Url(base64));

    $.ajax({

                beforeSend: function (xhr) {

 

                },

                type: 'POST',

                url: url,

                data: formDate,

                contentType: false,

                processData: false,

                success: function(data){

                   //成功回調

                },

                error: function (data) {

                   //失敗返回

                }

            })

})

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