Blitline canvas and composite

canvas_and_composilte.json

{
    "application_id":"YOUR_APP_ID",
    "src":{ "name" : "canvas",
                "width" : 500,
                "height" : 500,
                "color": "#ff0000"
            },
    "functions":[
        {
            "name":"composite",
            "params":{
                "src":"https://s3.amazonaws.com/img.blitline/grad_vignette_index.png",
                "gravity":"CenterGravity"
            },
            "save":{
                "extension":".png",
                "image_identifier":"MY_CLIENT_ID",
                "png_quantize":true
            }
        }
    ]
}