Image Catalog Tool

I thought I would start a dedicated section on my site for the Manifold GIS based Image Catalog Tool.

Image catalogs are used in ESRI technology, Manifold GIS and software such as the UMN MapServer. My image catalog tool, while not perfect, does (once you have mastered the tool and built some management practices around its use for your organisation) make the creation and management of image catalogs easier. It also facilitates the easy update of imagery in a catalog as well as the creation of single image mosaics from an image catalog.

The image catalog tool is more than just a tool to insert images into an image catalog. The tool comes with two components (a hyperlink means that there is an introductory video associated with the component or function being discussed).

The Catalog Registry Tool is used to create and manage an image catalog. Via this tool one can define an image catalog’s properties (metadata) and have the directory structure and shapefiles created. The metadata that is defined and managed by the Catalog Registry Tool makes the operation of the actual Image Catalog Tool far easier.

Once a catalog is defined one uses the Image Catalog Tool to add imagery to an image catalog. Adding imagery could entail the creation of new tiles or the updating of existing ones.

The Image Catalog Tool has many strengths over existing management tools.

  • It is free (expect for a Manifold GIS license of USD250);
  •  It enables an image catalog’s image quality to improve over time. It does this because if an existing tile has a pixel resolution that is coarser than any new image being added to the catalog that tile is upgraded to the smaller pixel resolution of the new imagery. In this way an image catalog’s image quality only improves over time and does not degrade. (See discussion on “minimum pixel size” in the Catalog Registry Tool.)
  • Single image mosaics can be generated from a set of image catalog tiles.
  • Multiple tile storage and “world file referencing” formats are supported.
  • A history record for each image that has been added to an image catalog can be created. The image’s spatial extent is saved as a footprint that can be visualised in a GIS.
  • A boundary shape defining the actual extent of the data is automatically created after each execution of the tool. This is useful for visualising areas in which tiles exist before zooming into particular areas.

The Image Catalog Tool is based on published science. This science allows us to define a optimum tile size for an image catalog so that disk access times are kept to a minimum improving visualisation response times in internet and interactive GIS use.

Over time I will add videos and documentation on all aspects of the tool until such a time as Manifold.Net incorporate the ideas in the tool into the product.