Application of Spectral Transformer B742B321: ELS2000 (global medium-resolution satellite imagery in simulated natural colours)

 

(1) Introduction

Spectral Transformer B742B321 is an advanced utility tool for producing high-quality, natural-colour imagery (equivalent to Landsat bands 3/2/1) from pan-sharpened, false-colour Landsat bands 7/4/2 at 14.25m resolution in NASA GeoCover series.

Medium-resolution, natural-colour Landsat imagery is an excellent and indispensable mapping layer for observing land covers in major virtual globes such as Google Earth and Microsoft Virtual Earth. The input for such global imagery is the enduring GeoCover Landsat series (related news), which is now publicly available in three main forms:

• ~8500 individual scenes with all separate bands at original spatial resolutions (28.5m) after Nearest Neighbour (NN) resampling. Such data are available at USGS GloVis or the Global Land Cover Facility. Spatial resampling schemes (Nearest Neighbour versus Cubic Convolution) used in inputs significantly affect subsequent image fusion and pan-sharpening result. (An illustration is provided here, and pan-sharpening with NN-based inputs is discouraged. Users can explore RGB Image Stretching Tool to produce 28.5m-resolution colour composites without performing pan-sharpening analysis.)

• The same number of individual scenes with pan-sharpened, false-colour bands 7/4/2 at 14.25m spatial resolution: During the initial pan-sharpening analysis, corresponding bands 7/4/2 were resampled with Cubic Convolution (CC) to ensure an outstanding pan-sharpene result. This is the best quality data source of its kind and available at USGS GloVis http://glovis.usgs.gov/. (also read the news release from USGS issued late 2005, and software tutorials below for more information.)

• ~880 colours balanced mosaic tiles made from the above ~8500 pan-sharpened scenes with Landsat false-colour bands 7/4/2. An uncompressed version in a lossless GeoTIFF format became downloadable at USGS GloVis http://glovis.usgs.gov/ from early June 2007. A compressed version in a lossy MrSID format is available from NASA Stennis Space Center https://zulu.ssc.nasa.gov/mrsid/ or the Global Land Cover Facility http://www.landcover.org/. Such global datasets may be ordered through USGS EROS.

Spectral Transformer B742B321 analyses pan-sharpened, false-colour Landsat bands 7/4/2 with the lineage of Cubic Convolution resampling (i.e., the above data sources 2 and 3). Both individual scenes and mosaic tiles are acceptable. For un-stretched individual scenes with full dynamic ranges, Spectral Transformer B742B321 includes intelligent, highly-efficient and time-saving image stretching methods; for mosaic tiles with color balancing already applied, B742B321 is also equipped with a number of color templates for false-to-true colour simulations.

This tool is of great potential use since pan-sharpened, 14.25m-resolution, false-colour imagery of Landsat bands 7/4/2 is now widely available in the public domain. Spectral Transformer B742B321 is the right tool for those who are interested in making visually-appealing and the best global Landsat imagery of its kind, with a full set of options enabling colour preferences and benchmarks. It can be licensed separately or as an add-on of HighView software.

(2) Command line - A powerful, easy-to-implement DOS command

Usage: b742b321.exe

b742b321.exe <image_source_indicator> <image_stretch_indicator>
<green_colour_coefficient>
<brightness_coefficient>
<in.tif> <out.tif>

Version: 2.25, released 02 July 2007

(3) Features and tutorials

Features list and three brief tutorials: PDF (file size ~1MB, new)

Colour templates illustrated: PDF (file size ~1MB, new)

Colour template examples: 1, 2 (Area: Sydney; Spatial resolution: 28.5m resampled from the original 14.25m)

(4) Samples

• Processed natural-colour, full-scene examples for evaluation - all at 14.25 m spatial resolution and simulated with the same colour template A in Spectral Transformer B742B321. In this case, the above best quality input source is used, ensuring extremely valuable outputs. Seeing is believing!
  
  With Spectral Transformer B742B321, the cost of processing each scene is far less than $1.

	Full-resolution small samples: JPEG file size 429KB New York / Mumbai / Kuala Lumpur / Paris / Seoul / Tokyo Bay Small-sized samples from Australia: Perth / Adelaide / Sydney
	Vancouver Full scene (image size 17738x15966 pixels, zipped JPEG file size 24.8MB, JPEG compression ratio ~30:1)
	Seattle Full scene (17698x16046, 16.7MB)
	San Francisco Full scene (17254x15490, 32.6MB)
	New Orleans Full scene (16956x15136, 26.2 MB)
	New York Full scene (17480x15488, 14.5MB)
	Washington, D.C. Full scene (18058x15986, 35.8MB)
	Paris Full scene (18114x16232, 32.7MB)
	Newcastle Upon Tyne, City of Edinburge Full scene (18160x16380, 11.4MB) JPEG compression ratio 40:1
	The Hague, Amsterdam Full scene (17482x15794, 16.8MB) JPEG compression ratio 40:1
	Geneva Full scene (17754x15668, 23.7MB) JPEG compression ratio 40:1
	Berlin Full scene (18210x16612, 16.1MB) JPEG compression ratio 40:1
	Hamburg Full scene (17928x16324, 20.9MB) JPEG compression ratio 40:1
	Jerusalem Full scene (17154x15146, 29.6MB)
	Kuala Lumpur Full scene (17276x15096, 25.1MB)
	Seoul Full scene (18086x15978, 29.4MB)
	Tokyo, Japan Full scene (17982x15980, 30.2MB)
	Nagoya, Japan Full scene (17366x15268, 14.5MB) JPEG compression ratio 40:1
	Osaka & Kyota, Japan Full scene (17420x15592, 16.7MB) JPEG compression ratio 40:1
	Kumamoto, Fukuoka & Kitakyushu, Japan Full scene (17432x15342, 13.0MB) JPEG compression ratio 40:1
	_____________________________________ Pyongyang, Democratic People's Republic of Korea (DPRK) - North Korea Full scene (17368x15306, 21.2MB) Reference at flashearth.com
	_____________________________________ North Korea - China border (Sinuiju - Dandong) Full scene (17568x15632, 31.8MB) Reference at flashearth.com

• Application of Spectral Transformer B742B321: Compressed 883 GeoCover mosaic tiles were converted into Earth Land Surface 2000 - global satellite imagery in simulated natural colour. (Spectral Transformer B742B321 with Image Source 2 and Colour Template 7 was employed to produce ELS2000.)
  
  
• Regional and continental false-colour mosaics of Landsat 5 Bands 7/4/2 (data heavily compressed and available at http://www.GeoTorrent.org) were converted into natural colour at ~120m spatial resolution. Processed data are downloadable at free data page.