navigator.camera.getPicture(onPhotoDataSuccess, onFail, { quality: ,        destinationType: destinationType.DATA_URL,targetWidth: ,targetHeight: ,correctOrientation:true });

function onPhotoDataSuccess(imageData) {

        saveImageToDB(imageData,);

        smallImage1.style.display = 'block';

        smallImage1.src = "data:image/jpeg;base64," + imageData;

    }

var imagePath = "img/OBseverLOGO.png";

        function convertImgToBase64(url, callback, outputFormat){

            var canvas = document.createElement('CANVAS'),

                ctx = canvas.getContext('2d'),

                img = new Image;

            img.crossOrigin = 'Anonymous';

            img.onload = function(){

                canvas.height = img.height;

                canvas.width = img.width;

                ctx.drawImage(img,,);

                var dataURL = canvas.toDataURL(outputFormat || 'image/png');

                callback.call(this, dataURL);

                canvas = null;

            };

            img.src = url;

        }

        //这里的imagePath用你的图片路径来替换;

        convertImgToBase64(imagePath, function(base64Img){

            alert(base64Img.length);

        });