image转Blobexport函数imageToBlob(src,cb){imageToCanvas(src,function(canvas){cb(dataURLToBlob(canvasToDataURL(canvas)))})}Blob转imageexportfunctionblobToImage(blob,cb){fileOrBlobToDataURL(blob,function(dataurl){varimg=newImage()img.src=dataurlcb(img)})}导出函数canvasToDataURL(canvas,format,quality){returncanvas.toDataURL(format||'image/jpeg',quality||1.0)}导出函数dataURLToBlob(dataurl){vararr=dataurl.split(',')varmime=arr[0].match(/:(.*?);/)[1]varbstr=atob(arr[1])varn=bstr.lengthvaru8arr=newUint8Array(n)while(n--){u8arr[n]=bstr.charCodeAt(n)}returnnewBlob([u8arr],{type:mime})}导出函数imageToCanvas(src,cb){varcanvas=document.createElement('CANVAS')varctx=canvas.getContext('2d')varimg=newImage()img.src=srcimg.onload=function(){canvas.width=img.widthcanvas.height=img.heightctx.drawImage(img,0,0)cb(canvas)}}导出函数fileOrBlobToDataURL(obj,cb){vara=newFileReader()a.readAsDataURL(obj)a.onload=function(e){cb(e.target.result)}}欢迎补充~~
