some maps display different features over a period of time
{"Image Orientation": "Horizontal (normal)", "Image XResolution": "300", "Image YResolution": "300", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS4 Windows", "Image DateTime": "2012:04:09 15:42:17", "Image ExifOffset": "164", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "302", "Thumbnail JPEGInterchangeFormatLength": "4150", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "910", "EXIF ExifImageLength": "598"}