Blue Marble Download Geotiff Maps

AboutAs an earth system scientist and ecologist I model ecosystem processes, such as vegetation growth or drought / disturbance resistance, using various -retrospective- proxy measurements in a model data fusion approach, including among others remote sensing, dendrochronology and recovered historical data records.Throughout my career I worked interdisciplinary borrowing heavily from fields, outside of ecology, such as image vision processing (computer science), remote sensing and engineering to assist in either field measurements and/or model driven analysis.–Koen Hufkens.

GeoTIFFGeoTIFF ImportOpen GeoTIFF or bigTIFF files by loading them directly into the application. The following file extensions are recognized automatically:.tif.,.itif.,.gtif.,.drg,.dng,.btf,.fx3.TIFF files that are not geospatial may also be loaded and georeferenced using the.GeoTIFF data will default to positioning using the information in the TIFF header. See for additional options. If projection information is found in the header, the application will look for a supported projection file format of the same name in the same directory, and use that (such as.tfw or.prj). ExportThe ExportGeoTIFF command allows the user to export any loaded raster, vector, andelevation data sets to a GeoTIFF format file.Export TIFF files from the File Export menu by choosing Export Elevation Grid Format. Or Export Raster/ Image Format. And specifying GeoTIFF as the Export Format.

Individual layers can also be exported from the Control Center by right-click on the layer and going to Layer  EXPORT. Multiple files can be batch converted to and from the format from the tool.When selected,the command displays the GeoTIFF Export Options dialog (pictured below)which displays export options. The dialog consists of a GeoTIFFOptions tab, a tab, and an tab which allowsthe user to set up the portion of the loaded vector data they wish toexport.File TypeThe FileType section allows you to choose what type of GeoTIFF file to generate.The various file types are described below:.8-bitPalette Image - This option generates a 256-color raster GeoTIFF filewith 8-bits per pixel. The Palette options described below will applyin this case.

In short, the SRTM and GTOPO elevation data was used to add hill shading to the Blue Marble imagery. The links below will allow you to download maps for various parts of the world. Quick warning, that the maps are very high resolution and some of them are very large downloads. I have also processed several of these with Microsoft SeaDragon.

This option will generate a relatively small outputfile, at the expense of some color fidelity depending on the palettethat you choose. The image data will be compressed using the PackBitscompression algorithm.24-bitRGB - This option generates a raster GeoTIFF file with 24-bits perpixel. Uncompressed GeoTIFF images generated with this option willbe at least 3 times the size of those generated with the 8-bit Paletteoption, but the colors in the image will exactly match what you seeon the screen. You can also maintain the exact colors while achievingsome compression using the LZW compression option. Selecting the JPEGcompression option generates a raster GeoTIFF file with 24-bits perpixel, but with the raster data compressed using the JPG compressionalgorithm. GeoTIFF images generated with this option will maintaingood color fidelity and often be highly compressed, although theywill lose some information as compared to the uncompressed 24-bitRGB option. If selecting this, option keep in mind that many software packages do not yet support GeoTIFF files thatuse the JPEG-in-TIFF compression option.

By default the JPG compressionused in the GeoTIFF file uses a quality setting of 75, which can bemodified on the displayed options dialog.Multi-band- This option generates a raster GeoTIFF file with 1 or more bandsof data at either 8-, 16-, or 32-bits per band of data. This optionis very useful when working with multi-spectral imagery with morethan 3 bands of data, such as RGBI, Landsat imagery, or data sets withmore than 8 bits per color channel. After selecting this option additional dialogs will be presentedallowing for further setup of the multi-band export by choosing theinput sources for each band in the output image.Blackand White - This option generates a two color GeoTIFF file with 1 bitper pixel. This will generate the smallest image of these options. However if thesource image had more than two colors the resulting image will bevery poor. By default, white will be a value of 0 and black will bea value of 1.

This can be reversed by selecting the Grayscale- Min Is Black palette option.Elevation(16-bit integer samples) - This option generates an elevation GeoTIFFusing the currently loaded elevation grid data sets. Elevation sampleswill be stored as signed 16-bit integers. Keep in mind there are only a handfulof software packages that correctly recognize a vertical GeoTIFF.Elevation(32-bit integer samples) - This option generates an elevation GeoTIFFusing the currently loaded elevation grid data sets. Elevation sampleswill be stored as signed 32-bit integers.

Check that vertical units are appropriate prior to using this option, intended for use with high resolution, sub-metric elevation data and values.Elevation(32-bit floating point samples) - This option generates an elevationGeoTIFF using the currently loaded elevation grid data sets. Elevationsamples will be stored as 32-bit floating point values. Keep in mind there are only a handfulof software packages that can correctly recognize a vertical GeoTIFF. The palette generated will be an optimal mix ofup to 256 colors that will closely represent the full blend of colorsin the source images.

This option will generate the best results,but can more than double the export time required if any high colorimages are present in the export set. If all of the input data ispalette-based and the combined palette of those files has 256 colorsor less, then the combined files of the input file will just be usedwith no additional export time being required. When converting from an existing palette image, the new image will be assigned the palette index (PAX IDX) of the closest matching RGB value in the new palette.

Resampling. NearestNeighbor - simply uses the value of the sample/pixel that asample location is in. When resampling an imagethis can result in a stair-step effect, but will maintain exactlythe original color values of the source image. BilinearInterpolation - determines the value of a new pixel based ona weighted average of the 4 pixels in the nearest 2 x 2 neighborhoodof the pixel in the original image. The averaging has an anti-aliasingeffect and therefore produces relatively smooth edges with less stair-step effect.

BicubicInterpolation - a more sophisticated method that produces smootheredges than bilinear interpolation. Here, a new pixel is a bicubicfunction using 16 pixels in the nearest 4 x 4 neighborhood of thepixel in the original image. This is the method most commonly usedby image editing software, printer drivers and many digital camerasfor resampling images. BoxAverage (3x3, 4x4, 5x5, and 7x7) - the box average methodssimply find the average values of the nearest 9 (for 3x3), 16 (for4x4), 25 (for 5x5), or 49 (for 7x7) pixels and use that as the valueof the sample location. These methods are very good for resamplingdata at lower resolutions. The lower the resolution of your exportis as compared to the original, the larger 'box' size youshould use. Filter/Noise/Median(2x2, 3x3, 4x4, 5x5, 6x6 and 7x7) - the Filter/Noise/Medianmethods simply find the median values of the nearest 4 (for 2x2),9 (for 3x3), 16 (for 4x4), 25 (for 5x5), 36 (for 6x6) or 49 (for 7x7)pixels and use that as the value of the sample location.

This resamplingfunction is useful for noisy rasters, so outlier pixels do not contributeto the kernel value. Some common sources of raster noise are previouscompression artifacts or irregularities of a scanned map/image. Kmspico v9.2.3.

BoxMaximum (3x3, 4x4, and 5x5) - the box maximum methods simplyfind the maximum value of the nearest 9 (for 3x3), 16 (for 4x4), 25(for 5x5), or 49 (for 7x7) pixels and use that as the value of thesample location. These methods are very good for resampling elevationdata at lower resolutions so that the new terrain surface has themaximum elevation value rather than the average (good for terrainavoidance). This method behaves the same as the average on raster/imagerylayers. The lower the resolution of the export file is as compared tothe original, the larger 'box' size that should be used.Sample Spacing / ScaleThe Sample Spacingsection allows the user to select the grid spacing to use when generatingthe file.