arcgis javascript API加载地图显示质量差的问题

用arcgis javascript API加载了地图服务以后,发现地图里图像比原图差,有点状的模糊


原来在加载图层的时候,可以指定图片格式,默认是png8,指定为jpg后就可以了

引用

var imageParameters = new ImageParameters();
        imageParameters.format = "jpeg"; //set the image type to PNG24, note default is PNG8.

        //Takes a URL to a non cached map service.
        var dynamicMapServiceLayer = new ArcGISDynamicMapServiceLayer("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Population_World/MapServer", {
          "opacity" : 0.5,
          "imageParameters" : imageParameters
        });