{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "title": "Image schema",
    "description": "Description of an image that is available for presentation of a step",
    "image": {
        "type": "object",
        "description": "data about a image",
        "properties": {
            "filename": {
                "type": "string",
                "description": "Filename of image in local filesystem"
            },
            "alt": {
                "type": "string",
                "description": "Alternative text for image"
            }
        },
        "required": [
            "filename"
        ],
        "additionalProperties": false
    },
    "properties": {
        "image": {
            "$ref": "#/image"
        }
    },
    "required": [
        "image"
    ]
}