Background Images

Background Image Manager

The Background images manager has been updated in music to provide support for a greater number of background image formats, display of multiple image files simultaneously and support for real world coordinates

MUSIC supports a large range of background image formats, as well as georeferencing (if provided as part of the selected image format). A summary of the image formats supported by music are provided below.

Image File Format DescriptionDefault File Extension
Arc/Info ASCII Grid*.txt;*.arc;*.asc
ADRG/ARC Digitilized Raster Graphics (.gen/.thf)*.gen
Arc/Info Binary Grid (.adf)*.adf
AIRSAR Polarimetric*.dat
Windows Bitmap*.bmp
BSB Nautical Chart Format (.kap)*.kap
VTP Binary Terrain Format (.bt)*.bt
CEOS (Spot for instance)*.ceos
Spot DIMAP (metadata.dim)*.dim
USGS DOQ (.doq)*.doq
Military Elevation Data (.dt0, .dt1, .dt2)*.dt
ERMapper Compressed Wavelets (.ecw)*.ecw
ESRI .hdr Labelled*.flt
Envisat Image Product (.n1)*.n1
Graphics Interchange Format (.gif)*.gif
GMT Compatible netCDF*.nc
Golden Software Grid*.grd
TIFF / GeoTIFF (.tif)*.tif
GXF - Grid eXchange File*.gxf
Hierarchical Data Format*.hdf
Intergraph Raster*.cot;*.ctc;*.rgb;*.ctb;*.grd;*.crl;*.tpe;*.lsr;*.rle;*.cit;*.g3;*.g4;*.tg4;*.cmp;
Erdas Imagine*.img
drisi Raster*.rst
Japanese DEM*.mem
JPEG*.jpg
JPEG2000*.jp2, *.jpk
Portable Network Graphics*.png
USGS SDTS DEM*CATD, *.ddf
Raster Matrix Format*.rsw; *.mtw
SRTM HGT Format*.hgt
USGS ASCII DEM*.dem
Multi-resolution Seamless Image Database*.sid

 

Georeferenced images

Many of the above file formats incorporate embedded georeferencing information. In such cases, music will extract this information and display the image in real world coordinates. It should be noted that music does not support re-projection of images. Therefore, if you intend to use multiple images, ensure that all images are georeferenced to a common coordinate system.

If an image does not contain embedded georeferencing information and the you wish to display the image with real world coordinates, it will be necessary to develop a 'world' file. A 'world' (*.wrl) file, is a text file comprising 6 lines of data that determines the location of the image in space. The world file can be created in any text editor. The file must comply with the following structure (information in brackets is for informative purposes only and is not to be included in the world file).

5.000000000000 (size of pixel in x direction in map units, e.g., metres)

0.000000000000 (rotation term for row, typically kept at 0)

0.000000000000 (rotation term for column, typically kept at 0)

-5.000000000000 (size of pixel in y direction in map units, e.g., metres. This should typically be a negative value)

492169.12000000 (x coordinate of upper left corner of image)

5426523.31000000 (y coordinate of upper left corner of image)

In addition, the *wrl file must have the same file name prefix as the image it is being associated with. For example, if you wished to create a world file for a Aerial_Background.jpg file, the world file would need to be called Aerial_Background.wrl.

 Tip Box

The pixel size in the y-direction will typically always be negative.

The coordinates of the cursor in a project are displayed in the bottom left hand corner of MUSIC.

Non-Georeferenced Images

If no georeferencing information is embedded in the image or included in a 'world' file, music will set the bottom left hand corner of the image to co-ordinates of x,y = 0,0 and the image size will

determine the maximum x and y coordinates of the display. For example, an image that is 1000 pixels high and 2000 pixels wide will have its lower left corner at 0,0 and its upper right corner at 2000, 1000.