Frame types
| qpx_FrameIsThumbnail | 0x0001 | Frame is an embedded thumbnail |
| qpx_FrameIsLayer | 0x0002 | Frame is a layer in a multi-layer image |
| qpx_FrameIsPage | 0x0004 | Frame is a page in a multi-page image |
| qpx_FrameIsMultiRes | 0x0008 | Frame is a resolution in a multi-res image |