MAPublisher has the ability to export placed raster files as georeferenced images for use in other applications or for archival purposes. This can be useful in a number of ways. For example, when working with an image for which there is no georeferencing file, use the MAPublisher Export Image function to create a georeferenced image file based on the coordinate system of the MAP View. If the MAP View contains georeferencing information, Export Selected Image can be used to save a raster layer to a georeferenced image format. MAPublisher can export selected images as TIFF, PNG or JPEG with several reference file format types or as a GeoTIFF, depending on whether the image is linked or embedded in the document.
Using Export Selected Image
An image must be selected first. From the MAPublisher Toolbar, click the Export button and click Export Selected Image.
In the Export Selected Image dialogue box, use the Export type drop-down list and choose to export both image and georeferencing file or just georeferencing. The Reference format drop-down list has several available georeferencing file formats: GeoTIFF, World (TFW), Blue Marble Reference (RSF), MapInfo Table (TAB), and ER Mapper (ERS). For reference formats that do not store coordinate system information, enable the Export coordinate system option to include a WKT or PRJ reference file. When exporting a linked image, the original image format can be saved, but the colour mode cannot be changed.
When exporting an embedded image, the colour mode can be changed to RGB, CMYK or grayscale (when applicable). Depending on the Adobe Illustrator document colour mode, the allowed image format may change when exporting embedded images:
Colour mode |
Allowed Image Format |
RGB |
TIFF, PNG, JPEG |
CMYK |
TIFF, JPEG |
Grayscale |
TIFF, PNG, JPEG |
Transparent RGB |
TIFF, PNG, JPEG |
Transparent CMYK |
TIFF, JPEG |
Transparent Grayscale |
TIFF, PNG, JPEG |
When exporting to a GeoTIFF, only a single file is produced (TIFF) since both the image and the georeference information are included in it. By default, the JPEG image quality setting is 75, the PNG compression level setting is 6, and the TIFF compression type is LZW.
MAP Image layers are not included when an entire MAP View is exported to a spatial format (e.g. Shapefile).
Exporting an image in BigTIFF format will not save the EXIF data.
Specify a name for the reference or image file and the folder location where it will be saved. A reference file will have the same file name as the image and will be saved in the same folder location.
Results
When the appropriate export options have been set, click the OK button. An exported image file can be subsequently used in imagery applications, such as Geographic Imager for Adobe Photoshop, in other Adobe Illustrator documents using MAPublisher, or in other geospatial applications.
Exporting a linked image in CMYK colour mode or an embedded image with existing transparency may create incorrect colour results. For the former situation, an image must either be set to a different colour mode or embedded. For the latter, the transparency must be removed from the source file.
When exporting linked images, alpha channels will be maintained. However, alpha channels are not maintained with embedded images during export.
If a MAP View is rotated, the exported image will not store any rotation parameter (it will be automatically rectified—oriented north up).
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