上传图片到后台，不需裁切的做法。

js部分：：：：
var file;
var reader = new FileReader();
var img = new Image();
// 上传图片
  var input = document.getElementById("vehicleListFiel");
    input.addEventListener( 'change',readFile,false);
    function readFile(){
        file = this.files[0];
        //      这里我们判断下类型如果不是图片就返回 去掉就可以上传任意文件
        if(!/image/w+/.test(file.type)){
            alert("请确保文件为图像类型");
            return false;
        }
        reader.readAsDataURL(file); 
        reader.onload=function (e) {       
                img.src =this.result;
                $("#vehicleListFielImgBox").empty();
                aa(img.src);
        }    
    }
    function aa(res) {
        $.ajax({
            type:"post",
            url:"{:U('Vehicle/index/uploadtest')}",
            data:{base64:res},
            dataType:'json',
            async:true,
            success:function(ee){
                if(ee.status==1){
                    $("#vehicleListFielImgBox").append('<img id="imgrote" style="100%;height:100%;" src="'+ee.info+'"/>');
                }else{
                    alert(ee.info);
                }
            },
            error:function(ee){
                alert(ee.info);
            }
        });
    }        

html部分：：：：         
   <label for="vehicleListFiel">
                <div id="vehicleListFielImgBox" style="100%;height:15rem;text-align:center; border:#e1e1e1 1px  dashed; border-radius:.4rem; -webkit-border-radius:.4rem; -moz-border-radius:.4rem; -o-border-radius:.4rem;overflow: hidden;">
                    <if condition="$vehicleInfo[0]['VehicleLicence'] eq ''"> 
                        <div style="100%;height:15rem;color:#999"> 
                            <span style="font-size:6rem;font-weight:100; margin-top:2rem; display:inline-block">+</span><br />
                            <span style="font-size:1.6rem; font-weight:bold;">车辆行驶证</span> 
                        </div>
                    <else />
                        <img src="__ROOT__/Uploads/VehiclePic/{$vehicleInfo[0]['VehicleLicence']}" alt="暂无图片" style="100%;height:100%;" ><span>{$vehicleList.statusName}</span> 
                    </if>
                </div>
                <input type="file" name="vehicleList" id="vehicleListFiel" style="display:none" value=""  capture="camera" accept="image/*">
            </label>

css样式（重要的是设置背景色和阴影）：

<canvas class="photo-canvas" id="photo-canvas" style="position: absolute;top:50%;left:50%;border:1px solid black;-webkit-transform:translate3d(-50%,-50%,0);transform:translate3d(-50%,-50%,0);z-index:3;background:none repeat scroll 0% 0% transparent;box-shadow:0 0 0 1000px rgba(0, 0, 0, 0.5);">
</canvas>