uSMART Raster

Load images virtually instantaneously
Batch Convert your images to many different formats
Clip your images to any shape(s)
Change the location, pixel size, orientation, etc. of your images
Multi-spectral images

The uSMART Raster Module has been optimised for image management and manipulation. uSMART Softcopy utilises this powerful Raster Engine to ensure smooth and fast panning in the stereo images. The module consists of four major categories namely uSMART Raster Configuration, uSMART Raster Batch Convert, uSMART Raster Batch Clip/Merge/Resample and uSMART Raster Viewer.

Raster Configuration
The Configuration routine is used to configure the way uSMART Reads (opens existing) and Writes (creates new) images. At first glance, this may seem unimportant and ineffectual, however upon closer scrutiny, it becomes clear why this routine is in fact extremely important.

Different image software and CAD packages vary with respect to the way they interpret the unit factors and geo-referencing formats that are used to place the images in terms of both positioning and size. Take the example of an Orthophoto created in uSMART. This Orthophoto may be geo-referenced correctly when viewed in a MicroStation design file, but it may not be geo-referenced when opened in another CAD package. This may naturally lead to frustration as the client battles to geo-reference the image in whatever software he/she might be using.

The geo-reference format of images created in uSMART can be set to origin and size (in the header or in a sister file), or transformation matrix providing further definition to the creation of orthophotos and other images. This is important because again software differs in its method of geo-referencing images.

Multi-spectral images can be created by setting the Number of bands and the Destination and Source of each band. Each band from the source image can be mapped to the same or differing destination band on the image being created. Therefore users can create e.g. false infrared images from RGBI source imagery.

Raster Batch Convert
The Batch Convert routine is used to convert and edit raster (image) files. Users can for instance move/copy images from a temporary drive to the system drive while at the same time setting items such as the format, geo-reference data, orientation, etc. as well as adding overviews. Overviews are generally added to improve "zoomed out" display speeds. They increase file sizes (± 33%) but they offer a remarkable speed advantage.

It should be noted that this routine utilises an extremely efficient method of making orthogonal rotations to images where only 1 byte in the image file is changed. This means that orthogonal rotations are very fast.

Most raster formats are supported in uSMART e.g. SmartTech Raster Files (*.str), Tagged-Image File Format (*.tif) and Intergraph Files (*.rgb, *.cot etc.), Joint Photographic Experts Group (JPEG) and ER Mapper Compressed Wavelet (ECW). This list will continuously grow with user requests.

JPEG support in TIFF files has been added to this already extremely efficient and powerful routine. Enhanced support for tiles within images has also been added, i.e. tiles are now efficiently read in uSMART. By combining JPEG compression in tiled TIFF files, highly efficient image panning can be achieved but with images at least 3 times smaller (or even considerably smaller than this).

It should always be remembered that it is not good practice to create a lossy compressed file (such as JPEG compression) from another lossy compressed file as further loss will occur.

A "Fast downsample factor" option has been added to the uSMART Raster Batch Converter for creating a down-sampled image from an existing image. If the source image contains overviews, which were previously generated using this routine, then an overview of the source image will be used but if overviews do not exist, the image is decimated by the required factor. This will then produce results of a lower quality than when overviews exist in the source image. Due to the exceptional speed of this routine the down-sampling factor is restricted to the following options: 2, 4, 8, 16 etc. This routine can be very effectively used for sample images, book prints (thumbnails) etc.

Raster Batch Clip/Merge/Resample
The Batch Clip/Merge/Resample routine is used to clip, merge and resample raster (image) files. Many packages use the term "mosaic" for the merging etc. of images. uSMART divides the "mosaicing" up into a 3 step process which can often be run simultaneously but users also have the option of executing each process separately.

This "mosaicing" process is as follows:
1) Balance the images so that their brightness and contrast etc. are the same.
2) Feather the images so that no joins can be seen where they meet.
3) Clip and/or merge the images into user-defined shapes or even just 1 large image.

Although "mosaicing" could probably be the primary function of this routine, it can be seen that it is not limited only to this. Here are some of the other possible applications that this routine can be used for:
1) Stamp (or merge) a portion (or all) of an image (or images) into another.
2) Resample image(s) to increase or decrease the number of pixels.
3) Change the background colour(s) of image(s) to a new colour.

Averaging of the pixels can be done where images overlap. In this way basic feathering (unweighted) is done to ensure a seamless join. Weighted feathering should normally be done BEFORE this routine is utilised. Images with differing pixel sizes can also be merged or clipped. The Raster Batch Clip routine uses your shapes to determine the origin of the new image (when not stamping). Users should therefore expect a slight shift in pixels i.e. up to half the output pixel size although this effect can be greatly reduced (or eliminated) by using the Bilinear or Cubic Convolution sampling methods and using a smaller pixel size than the source. If Nearest Neighbour is to be used then the minimum point of all the shape(s) should fall exactly on a pixel multiple of the source image to eliminate this shift effect.

Raster Viewer
The Raster Viewer routine is used to display raster files in uSMART windows and MicroStation Views. It can however also be used to simply display and/or print details about a raster file. Settings such as image borders, transparent (background) colour, dynamic adjustments of contrast and brightness and multi-spectral options e.g. Infrared can be applied and/or adjusted in the viewer. One can also view and output the image histogram using this routine to acquire further information about the image(s).

Users can select which bands to display if the image has multiple bands e.g. RGBI imagery. There are some predefined options to select from e.g. False Colour Infrared or alternatively users can "map" the bands to display. (Please keep in mind that only three bands can be displayed on most computer monitors i.e. conventionally Red, Green and Blue (RGB).)

It is easy to change the Location of images and "pack them out" using for example tiles. Images can be placed interactively, dragged to new locations, scaled, rotated, etc. without permanently changing the image geo-referencing information. This is a great tool for Softcopy users to "pack out" the images according to the flight lines and ensure that the overlaps, rotations, etc. are correct before starting the project.