The scaling option gives you an oppurtunity to specify the maximum size of uploading images. If the size is bigger than the one specified by you, the image size will be scaled to your size values.
You may also change the quality of uploading images in a range from 1 to 100. To apply these options you should change values in this section:
config.images.maxWidth = 1600; config.images.maxHeight = 1200; config.images.quality = 80;