The Export BSB Marine Chart command allows the user to export any loaded raster, vector, and elevation grid data sets to a palette-based (up to 127 colors) BSB marine chart raster image for use in compatible applications and some marine chart plotters. The export will generate a single KAP file containing the chart image.
When selected, the command displays the BSB Export Options dialog which allows the user to setup the export. The dialog consists of a General options panel which allows the user to set up the pixel spacing and chart parameters, a Tiling Panel, and an Export Bounds panel which allows the user to set up the portion of the loaded data they wish to export.
Specify the chart name to be included in the metadata
Specify the chart number to be included in the metadata
Specify the edition date for the raster chart
Specify the chart scale. Use 0 to automatically determine the scale based on the sample spacing and image size.
Specify the depth and height units
Specify the dots per inch of the image.
Specify the color palette to use in the chart.
Image
Optimized Palette - The palette generated will be an optimal mix of
up to 256 colors that will closely represent the full blend of colors
in the source images. This option will generate the best results,
but can more than double the export time required if any high color
images are present in the export set. If all of the input data is
palette-based and the combined palette of those files has 256 colors
or less, then the combined files of the input file will just be used
with no additional export time being required.
Grayscale
Palette - This palette consists of 256 scales of gray ranging from
black to white.
DRG
Optimized Palette - This palette is optimized for the exporting USGS
DRG data. The palette consists of only the standard DRG colors.
DRG/DOQ
Optimized Palette - As the name suggests, this palette is optimized
for exporting a mixture of USGS DRG data and grayscale satellite photos
(i.e. USGS DOQs). The palette consists of the 14 standard DRG colors
with the remaining 242 colors being a range of gray values ranging
from black to white.
Halftone
Palette - The palette consists of a blend of 256 colors evenly covering
the color spectrum. This palette is the best choice when exporting
anything but DRGs and grayscale satellite photos.
Custom
Palette from File - This option allows the user to choose a .pal file
describing the palette to use for the export. A .pal file should be
a text file with one line per color, with the red, green, and blue
color components for each color in the palette separated by a comma.
A .pal file for an existing palette-based file can be saved by opening
the Overlay Control Center, selecting the palette-based layer,
Options, Transparent Color button, then selecting the option
to save a color palette file.
Grayscale
- Min is Black Palette - This palette creates an 8-bit per pixel grayscale
image with no color map stored in the image. Black will be stored
as zero with varying shades of gray up to white with a value of 255.
Grayscale - Min is White Palette - This palette creates an 8-bit per pixel grayscale image with no color map stored in the image. White will be stored as zero with varying shades of gray up to black with a value of 255.
The Sample Spacing section allows the user to select the grid spacing to use when generating the file. The default value is the average of the grid spacings of all the currently loaded raster and elevation overlays.
If the Always Generate Square Pixels option is checked, the smaller of the specified x and y resolutions will be used for both the x and y resolution.
Selecting Always Generate Square Pixels ensures that the resultant image file will look good even in software that is not able to deal with pixels that aren't square.
To specify the spacing in units other than those of the currently selected view/ export projection, press the Click Here to Calculate Spacing in Other Units button.
Check this option to include displayed map elements in the export. These are enabled from Configuration Display Options
Geographic Coordinates can be converted to pixel coordinates using polynomials. This is a high accuracy transformation method that not all chart reading programs utilize. The image position is the alternative spatial locating method. Check this option to include the polynomial transformation in the KAP file