Croppie：如何获取JPEG而不是默认PNG的输出图像？

问题描述

我使用cropie在laravel应用程序中上传图像。上载部分完美无缺。但是，由于PNG图像比原始图像占用更多空间。我想将jpeg图像而不是PNG存储在服务器上，并提供自己的质量参数。

这是我用来通过裁剪上传图片的javascript代码。 但以PNG格式保存图像

$(function() {
    var croppie = null;
    var el = document.getElementById('resizer');

    $.base64ImagetoBlob = function(str) {
        // extract content type and base64 payload from original string
        var pos = str.indexOf(';base64,');
        var type = str.substring(5,pos);
        var b64 = str.substr(pos + 8);
      
        // decode base64
        var imageContent = atob(b64);
      
        // create an ArrayBuffer and a view (as unsigned 8-bit)
        var buffer = new ArrayBuffer(imageContent.length);
        var view = new Uint8Array(buffer);
      
        // fill the view,using the decoded base64
        for (var n = 0; n < imageContent.length; n++) {
          view[n] = imageContent.charCodeAt(n);
        }
      
        // convert ArrayBuffer to Blob
        var blob = new Blob([buffer],{ type: type });
      
        return blob;
    }

    $.getimage = function(input,croppie) {
        if (input.files && input.files[0]) {
            var reader = new FileReader();
            reader.onload = function(e) {  
                croppie.bind({
                    url: e.target.result,});
            }
            reader.readAsDataURL(input.files[0]);
        }
    }

    $("#file-upload").on("change",function(event) {
        $("#myModal").modal();
        // Initailize croppie instance and assign it to global variable
        croppie = new croppie(el,{
                viewport: {
                    width: 200,height: 200,type: 'circle'
                },boundary: {
                    width: 250,height: 250
                },enableOrientation: true
            });
        $.getimage(event.target,croppie); 
    });

    $("#upload").on("click",function() {
        croppie.result('base64','original','jpeg',0).then(function(base64) {
            $("#myModal").modal("hide"); 
            $("#profile-pic").attr("src","/images/ajax-loader.gif");

            var url = "{{ url('/demos/jquery-image-upload') }}";
            var formData = new FormData();
            formData.append("profile_picture",$.base64ImagetoBlob(base64));

            // This step is only needed if you are using Laravel
            $.ajaxSetup({
                headers: {
                    'X-CSRF-TOKEN': $('Meta[name="csrf-token"]').attr('content')
                }
            });

            $.ajax({
                type: 'POST',url: url,data: formData,processData: false,contentType: false,success: function(data) {
                    if (data == "uploaded") {
                        $("#profile-pic").attr("src",base64); 
                    } else {
                        $("#profile-pic").attr("src","/images/icon-cam.png"); 
                        console.log(data['profile_picture']);
                    }
                },error: function(error) {
                    console.log(error);
                    $("#profile-pic").attr("src","/images/icon-cam.png"); 
                }
            });
        });
    });

    // To Rotate Image Left or Right
    $(".rotate").on("click",function() {
        croppie.rotate(parseInt($(this).data('deg'))); 
    });

    $('#myModal').on('hidden.bs.modal',function (e) {
        // This function will call immediately after model close
        // To ensure that old croppie instance is destroyed on every model close
        setTimeout(function() { croppie.destroy(); },100);
    })

});

解决方法

我不久前也遇到过类似的问题。

我按照文档使用 jQuery 方式。 OP 也在其他地方使用 jQuery，所以...

Croppie 是这样附加的：

upload = $('#upload_div').croppie(method,args);

而不是像这样传递参数：

croppie.result('base64','original','jpeg',0).then(function(base64){...

您传递命名参数：

  upload.croppie(
  'result',{type: 'base64',size: 'original',format: 'jpeg',quality: 0
  }).then(function(base64){ ...