@title{WORKS}{Shared Works Controls} The following topics are for GUI controls, shared between some or all Works programs (ImageWorks, GCPWorks, ...). See Also: {IWORKS}ImageWorks, GCPWorks 1 Data File Manipulation All Works programs share a common interface for creating, selecting, reading, and writing image and auxiliary information to disk files. The Works data file manipulation capabilities include reading and writing image data, graphic data, vector data, LUTs, and PCTs to a variety of data file formats, including PCIDSK, TIFF, X Window Dump, Intergraph COT, ARC/Info Generate, Erdas .LAN and .GIS, and Sun Raster files. 2 File Selection Panel The file selection panel is used to select database files for a variety of purposes. It typically can be used to select any supported database type, including PCIDSK, TIFF, X Window Dump, Sun Raster, Raw Imagery, Intergraph Continuous Tone (COT), Erdas (.lan or .gis), and ARC/INFO Generate vectors. The file selection panel can be invoked from the ``Open'' entry of the ``File'' pulldown menu. It is also popped up any time a Load or Save operation is requested, when there is not yet a selected file. The file selection panel is a standard Motif File Selection Dialog. To select an image file, double click on the Selection box, type the file name, and hit enter. Other methods of interaction with the File Selection Dialog are described in the OSF/Motif User's Guide. If the selected file does not exist, the user will be asked if a new file should be created. If the file is of no recognized format, the user will be asked whether to describe the file as a raw imagery file via the Raw Imagery File Definition panel, or to cancel the selection. The following topics describe details of the support for the various file formats. See Also: {..|raw imag}Defining Raw Files, {..|}GDB File Formats 2 GDB File Formats PCI's Works programs use a Generic DataBase library (GDB) to access image, and auxiliary information from data files. This allows different file types to be used interchangeably where it makes sense for the file type. To access a file, it is normally just necessary to select it with the File Selection Panel, regardless of the format. The GDB library will recognize the file if it is a supported format. To create new files of a supported format, use the File Creation Panel; however, note that some file formats can be read, but not written or created. See Also: {GDB|}Supported File Formats, {..|}File Selection Panel, {..|}File Creation 2 Raw Imagery File Definition Panel When an unrecognizable file is selected using the File Selection Panel, the user is given the option of defining it as a Raw Imagery File. This panel is used to define the format of the raw imagery file. The ``Cancel'' button can be used if the user decides not to define the selected file as a raw imagery file. Following is a description of fields on the panel: 3 Header Bytes This field specifies how many bytes at the beginning of the file represent header information to be ignored. The default value is zero, indicating that the imagery data starts right at the beginning of the file. 3 Image Size These two fields define the X (Pixel) and Y (Line) size of the image in the imagery file. These should be the full size of the image in the file, even if the user only wishes to load a subwindow of the whole file. 3 Number of Channels Indicates the number of channels or planes of image data stored in the file. This value defaults to 1. 3 Data Interleaving Indicates how multiple channels of image data are interleaved. This field is not applicable for 1 channel image files. Possible choices are as follows: - PIXEL: the channels are pixel interleaved. For instance, for a three channel file, the values in the file would be 123123123..., with the channel values for a given pixel located together. - LINE: The channels are line interleaved. The data for line 1 of the first channel occurs first, followed by the data for line 1 of the second channel and line 1 of the third channel. Next is line 2 of the first channel, etc. For instance, for a three channel file, the values in the file would be (line 1)111...222...333(line 2)111...222...333... - BAND: The channels are band sequential. All the data for the entire first channel would be first, followed by all the data for the second channel, etc. 3 Data Type This field is used to define the size and meaning of the data read for each pixel. - 8 bit: The data for each channel of each pixel are 8 bit, unsigned. Values range from 0 to 255. - 16 bit Unsigned: The data for each channel of each pixel are 16 bit, unsigned. Values range from 0 to 65535, and are two bytes each. - 16 bit Signed: The data for each channel of each pixel are 16 bit, signed. Values range from -32768 to 32767, and are two bytes each. - 32 bit Real: The data for each channel of each pixel are 32 bit IEEE floating point numbers. Each value is 4 bytes long. 3 Saving Raw Configuration When the ``Accept'' button in in the Raw Imagery Definition panel is pressed the user is asked if they would like to save their raw definition of the image file. If they answer yes a new header file with the extension .aux and the same basename as the file being defined will be created. This file will contain information on the layout of the imagery as provided by the user. Whenever the image file is selected in the future by a program with Generic DataBase (GDB) support (such as ImageWorks) the file will be automatically recognised without being redefined. The following is an example of the file produced for a simple 1000x1000 eight bit single channel image. AuxiliaryTarget: rawimage.bil RawDefinition: 1000 1000 1 ChanDefinition-1: 8U 0 1 1000 Swapped If the .aux file cannot be written due to the permissions on the directory in which the target file is stored there will be no error message generated; however, the user will have to define the file each time it is used. Also note that one the .aux file is created the user will not get an opportunity to define the raw file again until the .aux file is deleted.. Therefore when experimenting with possible raw file definitions it is best not to create an .aux file. See Also: GDB 2 File Creation The New File Type selection panel allows the user to select the type of database file to create. If the user does not want to create a file, the Cancel button should be pressed. This panel is invoked from the File Selection panel by entering the name of a file that does not exist, or from the main menu bar by selecting the ``New'' entry from the ``File'' pulldown menu. To create a new database file, select the type of file desired and hit OK. A panel specific to the desired file type will be popped up, allowing for the setting of specific creation information. Once the file is created, it will become the currently selected file and data may be saved in it. The action of creating a file does not write any data to the file, this must be done explicitly using the various save panels. Newly created files are not necessarily written completely to disk till the program is exited, or another file is selected. The ARC/Info Generate, AutoCAD DXF, DLG-3 and GRASS Vector file types require no additional information and will be created immediately after the OK button is selected. 3 PCIDSK File Creation The PCIDSK File Creation panel allows the user to enter the desired filename, description, size, channel data type, and georeferencing information for a new PCIDSK database file. The Facility and Description fields contain optional comment information stored in the file header. The georeferencing system and bounds of the new file may be specified with the GeoEdit control. The user will be prompted for confirmation before the file is created. See Also: {GDB|Supported|PCIDSK}PCIDSK Details, GeoEdit 3 TIFF File Creation The TIFF File Creation panel allows the user to enter the desired file name, size, and configuration. A TIFF file may be in one of three configurations. It may be an RGB file (three channels, TIFF R), a single eight bit channel with an optional Pseudocolour Table (TIFF G or P) or a single bitmap (TIFF B). Georeferencing information for the TIFF file may be specified using the GeoEdit control. Note that the georeferencing will be placed in an additional text file (with the extension .aux) and will not be recognised by any package except EASI/PACE. After the file name, configuration, and database size have been set, the ``Create'' button will proceed to create the requested file. It is not possible to create compressed TIFF files. The PACE task TIFFWR must be used for that. See Also: FEXPORT, {GDB|Supported|TIFF}TIFF Details, GeoEdit 3 Laser-Scan File Creation The Laser-Scan File Creation panel allows the user to enter the desired file name, size, and configuration. A Laser-Scan file may be in one of the five supported types. It can be an uncompressed greyscale, compressed pseudo-coloured, uncompressed RGB, uncompressed bitmap and uncompressed pseudo-coloured. It is not possible to create the type 1 and 6 (compressed bitmap) formats of Laser-Scan files. Note that there is only one opportunity to save to compressed Laser-Scan files using the ``Save Imagery'' panel. See Also: FEXPORT, {GDB|Supported|Laser}Laser-Scan Details 3 X Window Dump File Creation The X Window Dump File Creation panel allows the user to enter the desired file name, size, and configuration. An X Window dump file may be in one of four configurations. It may be an RGB file (three channel) with or without LUTs, or a single eight bit channel with an optional Pseudocolour Table. The RGB files without LUTs, and eight bit files with PCTs are most likely to be supported by other software that reads and writes X Window Dump files. After the file name, configuration, and database size have been set, the ``Create'' button will proceed to create the requested file. It will then become the currently selected file. The ``Cancel'' button may be used to abort file creation; control will be returned to the file selection panel. See Also: FEXPORT, {GDB|Supported|X Win}X Window Dump Details 3 Sun Raster File Creation The Sun Raster File Creation panel allows the user to enter the desired file name, size, and configuration. An Sun Raster file may be have either one, or three image planes. After the file name, configuration, and database size have been set, the ``Create'' button will proceed to create the requested file. It will then become the currently selected file. The ``Cancel'' button may be used to abort file creation; control will be returned to the file selection panel. If the created file has one image plane, it will also have an associated PCT. If an RGB file is created each band will have an associated LUT, though many packages may ignore it. See Also: FEXPORT, {GDB|Supported|Sun}Sun Raster Details 3 Erdas .LAN and .GIS File Creation The Erdas File Creation panel allows the creation of 8 bit or 16 bit Erdas .LAN or .GIS files with a requested file name, size, and number of channels. When .LAN files are created, only one channel should be selected. Note that it is not possible to create Erdas 4 bit files, and that all files created are the Erdas 7.4 format. The new version 8.0 format is not supported. The georeferencing system, and bounds for the output file can be set with the GeoEdit control. Note that of the visible georeferencing systems, only Long/Lat, and UTM will be accurately exported in the Erdas file. After the file name, georeferencing, data type, database size, and number of channels have been set, the ``Create'' may be used to create the requested file. It will then become the currently selected file. The ``Cancel'' button may be used to abort file creation. See Also: FEXPORT, {GDB|Supported|Erdas}Erdas Details, GeoEdit 3 GRASS Cell File Creation The Grass Cell File Creation panel allows the creation of a GRASS Cell file with a requested file name, size, format and Georeferencing information. After the file name, database size, and format have been specified with the appropriate georeferencing information, the ``Create'' button can be used to create the file. Note that only UTM georeferencing is reliably supported when creating GRASS raster layers. There are two ways to specify where the new cell file should be created. One is to specify the entire path to the cell header in the ``cellhd'' directory. The other is to supply on the layer name, but this requires that a valid .grassrc be supplied. In this case the cell will be placed in the current MAPSET from the .grassrc file. It is also imperative that the user have already created the ``cell'' and ``cellhd'' directories, and that they be writable before trying to create a new cell. See Also: {GDB|Supported|GRASS}GRASS Details, GeoEdit 2 Loading Image Data The Load Imagery Panel allows the user to select one or more channels to be loaded from the currently selected file, to selected image planes in memory. A subwindow of data may also be selected. The Database Channels and Database Window Selection areas of the panel are described in the following subtopics. When the desired channel load mapping and input window have been chosen, the ``Load'' button will load the image channels but leave the load panel visible. The ``Load And Close'' button will load the requested image channels, and pop the panel down. The ``New File'' button is used to select a new database from which to load. 3 Database Channels The ``Database Channels'' section of the Load Imagery panel allows the user to select the image channels to be loaded by clicking on them. The database channels are found in a scrollable list with a description of the source data type, and a descriptor from the file. Beneath the scrollable list is a series of channel mapping pairs. On the left of each pair is the number of an image plane in memory, and on the right is a blank field into which a database channel number can be placed. When one of the right side text fields contains a number, it indicates that the corresponding image plane in memory will be loaded from the database channel. For example, the following mapping would indicate that channels 1 and 2 from the database will be loaded into image planes 2 and 3 in memory. 1 : _ 2 : 1 3 : 2 Beneath the channel mapping pairs, are Clear and Default action buttons. Pressing the Clear button erases the current channel map, while pressing the Default button establishes a default channel mapping. 3 Database Window Selection The Database Window Selection is found beneath the Database Channels section. On the left of this area is a box containing a subwindow box. The outline box is a graphic representation of the selected database, while the subwindow box is a graphic representation of the subwindow of data to be loaded from the selected database. By default, the loaded subwindow is the whole database. The size, shape, and placement of the subwindow may be manipulated with the mouse in a manner very similar to window resizing. A textual version of the database subwindow to be loaded is located to the right of the graphical view. It is shown in the usual EASI/PACE form: X Offset, Y Offset, X Size, Y Size This text field may be edited to modify the loaded subwindow. Three action buttons are also available. The Overview button resets the subwindow to be the whole database area. The Full Res (Full Resolution) button forces the window size to be no larger than the size of the in-memory image planes. This ensures that image data is being loaded at full resolution. The 1:1 Aspect ratio button clips the image window to make the database loading subwindow the same shape as the in-memory image planes. This ensures that at a zoom level of 1 or more, the viewed data will have a 1:1 aspect ratio relative to the database. This aspect ratio correction does not account for distortion due to pixel size when displayed on the monitor. 2 Loading Graphic Data The Load Graphics panel allows the user to select one or more channels to be loaded from the currently selected file, to selected graphic planes in memory. A subwindow of data may also be selected. The Database Bitmap Segments and Database Window Selection areas of the panel are described in the following subtopics. When the desired bitmap load mapping and input window have been chosen, the ``Load'' button will load the bitmap segments, but leave the load panel visible. The ``Load And Close'' button will load the requested bitmaps, and pop the panel down. The ``New File'' action button is used to select a new database from which to load. 3 Database Bitmap Segments The ``Database Bitmap Segments'' section of the Graphic Load panel allows the user to select the bitmap segments to be loaded by clicking on them. The database bitmaps are found in a scrollable list with a descriptor. Beneath the scrollable list is a series of bitmap mapping pairs. On the left of each pair is the number of a graphic plane in memory, and on the right is a blank field into which a database segment number can be placed. When one of the right side text fields contains a number, it indicates that the corresponding graphic plane in memory will be loaded from the database bitmap segment. For example, the following mapping would indicate that segments 3 and 4 from the database will be loaded into graphic planes 2 and 3 in memory. 1 : _ 2 : 3 3 : 4 Beneath the segment mapping pairs, are Clear and Default action buttons. Pressing the ``Clear'' button erases the current segment map, while pressing the Default button establishes a default segment-to-graphic mapping. 3 Database Window Selection The Database Window Selection area is found beneath the Database Bitmap Segments section. On the left of this area is a box containing a subwindow box. The outline box is a graphic representation of the selected database, while the subwindow box is a graphic representation of the subwindow of data to be loaded from the selected database. By default, the loaded subwindow is the whole database. The size, shape, and placement of the subwindow may be manipulated with the mouse in a manner very similar to window resizing. A textual version of the database subwindow to be loaded is located to the right of the graphical view. It is shown in the usual EASI/PACE form: X Offset, Y Offset, X Size, Y Size This text field may be edited to modify the loaded subwindow. Three action buttons are also available. The ``Overview'' button resets the subwindow to be the whole database area. The ``Full Res'' (Full Resolution) button forces the window size to be no larger than the size of the in-memory graphic planes. This ensures that graphic data is being loaded at full resolution. The 1:1 Aspect ratio button clips the load window to make the database loading subwindow the same shape as the in-memory graphic planes. This ensures that at a zoom level of 1 or more, the viewed data will have a 1:1 aspect ratio relative to the database. This aspect ratio correction does not account for distortion due to pixel size when displayed on the monitor. 2 Loading Vector Data The Load Vectors panel allows the user to load new vector layers one at a time from a database file. Each load operation creates one new vector layer in memory. Each newly loaded vector layer is placed at the highest level of priority relative to the other vector layers. To load a vector layer, select the layer from the scrollable list of ``Database Vector Segments''. The "Load" action button will load the vector segment, but leave the load panel visible. The ``Load And Close'' button will load the vector segment, and pop the panel down. The ``New File'' action button is used to select a new database from which to load. 2 Loading LUTs The Load LUT (Lookup Table) panel allows the user to select one or more LUTs to be loaded from the currently selected file and to be associated with selected image planes. The ``Database LUT Segments'' section of the Load LUT panel allows the user to select the LUT segments to be loaded by clicking on them. The database LUTs are found in a scrollable list with a descriptor. Beneath the scrollable list is a series of LUT mapping pairs. On the left of each pair is the number of an image plane in memory, and on the right is a blank field into which a database LUT segment number can be placed. When one of the right side text fields contains a number, it indicates that the corresponding image plane in memory will be associated with the LUT loaded from the LUT segment. For example, the following mapping would indicate that LUT segments 3 and 4 from the database will be loaded and associated with image planes 2 and 3 in memory. 1 : _ 2 : 3 3 : 4 Beneath the segment mapping pairs are Clear and Default action buttons. Pressing the ``Clear'' button erases the current segment map, while pressing the Default button establishes a default segment to image plane mapping. When the desired LUT segment to image plane load mapping has been established, the ``Load'' button will load the LUT segments, but leave the load panel visible. The ``Load And Close'' button will load the requested LUTs, and pop the panel down. The ``New File'' action button is used to select a new database from which to load. 2 Loading PCT Data The PCT (Pseudo Colour Table) loading panel allows the user to load a PCT segment from a database, to replace the PCT currently in memory. To load a PCT segment, select the layer from the scrollable list of ``Database PCT Segments''. The ``Load'' action button will load the PCT segment, but leave the load panel visible. The ``Load And Close'' button will load the PCT segment, and pop the panel down. The ``New File'' action button is used to select a new database from which to load. 2 Saving Image Data The image saving panel allows the user to save one image plane from in-memory to an image channel on a database file. While the entire ImageWorks data area is always saved, the user can specify a subwindow of the database channel to which the image plane data is saved. The image plane data is decimated to fit the specified subwindow. The save panel is divided into four subareas, which are described in the following subtopics. When the desired channel mapping and output window have been chosen, the ``Save'' button will save the image plane, but leave the save panel visible. The ``Save And Close'' button will save the requested image plane, and pop the panel down. The ``New File'' action button is used to select a new database to which to save the image plane data. 3 Planes and Channels The ``Savable Image Planes'' section of the Image Save panel is used to select an in-memory image plane to save to the disk file. It is a scrollable list of image planes, and the selected image plane to be saved is highlighted. The ``Database Channels'' section of the Image Save panel is used to select a channel on the database file to which to save the in-memory image plane. It is a scrollable list of image channels, and the selected channel to which the image plane data will be saved will appear highlighted. It is necessary that both a savable image plane and a database channel be selected before imagery can be saved. 3 Database Window Selection The Database Window selection area is found beneath the Database Channels section. On the left of this area is a box containing a subwindow box. The outline box is a graphic representation of the selected database, while the subwindow box is a graphic representation of the database subwindow to which the image plane data will be saved. By default, the subwindow is the whole database. The size, shape, and placement of the subwindow may be manipulated with the mouse in a manner very similar to window resizing. A textual version of the database subwindow to which imagery will be saved is located to the right of the graphical view. It is shown in the usual EASI/PACE form: X Offset, Y Offset, X Size, Y Size This text field may be edited to modify the subwindow. Three action buttons are also available. The Overview button resets the subwindow to be the whole database area. The Full Res (Full Resolution) button forces the window size to be no larger than the size of the in-memory image plane. This ensures that image data is being saved at full resolution. The 1:1 Aspect ratio button clips the image window to make the database subwindow the same shape as the in-memory image plane. This ensures that the aspect ratio of the image data is preserved. 3 Channel Information The Channel Information area is used to modify the channel description to be saved with the image plane. The number of the currently selected image channel is shown beside the Number field. 2 Saving Graphic Data The Save Graphic panel allows the user to save one graphic plane from in-memory to a bitmap segment on a database file. While the entire ImageWorks graphic data area is always saved, the user can specify a subwindow of the database channel to which the graphic plane data is saved. The graphic plane data is decimated to fit the specified subwindow. The save panel is divided into four subareas, which are described in the following subtopics. When the desired graphic plane to bitmap segment mapping and output window have been chosen, the ``Save'' button will save the graphic plane but leave the save panel visible. The ``Save And Close'' button will save the requested graphic plane, and pop the panel down. The ``New File'' action button is used to select a new database to which to save the graphic plane. 3 Graphics Planes and Bitmaps The ``Savable Graphic Planes'' section of the Graphic Save panel is used to select an in-memory graphic plane to save to the disk file. There is a scrollable list of graphic planes, and the selected graphic plane to be saved is highlighted. The ``Database Bitmap Segments'' section of the Graphic Save panel is used to select a bitmap segment on the database file to which the graphic plane will be saved. It is a scrollable list of bitmap segments, and the selected bitmap segment to which the graphic plane will be saved will appear highlighted. If the database file, to which the graphic plane will be saved, is a PCIDSK file, it is not necessary to select a bitmap segment. If no target bitmap segment has been selected, or the ``Number'' field of the Segment Information area has been cleared, a new bitmap segment will be created. 3 Database Window Selection The Database Window Selection is found beneath the Database Bitmap Segments section. On the left of this area is a box containing a subwindow box. The outline box is a graphic representation of the selected database, while the subwindow box is a graphic representation of the database subwindow to which the graphic plane will be saved. By default, the subwindow is the whole database. The size, shape, and placement of the subwindow may be manipulated with the mouse in a manner very similar to window resizing. A textual version of the database subwindow to which the graphic plane will be saved is located to the right of the graphical view. It is shown in the usual EASI/PACE form: X Offset, Y Offset, X Size, Y Size This text field may be edited to modify the subwindow. Three action buttons are also available. The Overview button resets the subwindow to be the whole database area. The Full Res (Full Resolution) button forces the window size to be no larger than the size of the in-memory graphic plane. This ensures that image data is being saved at full resolution. The 1:1 Aspect ratio button clips the image window to make the database subwindow the same shape as the in-memory graphic plane. This ensures that the aspect ratio of the graphic data is preserved. 3 Segment Information The Segment Information area is used to modify the segment name and description, to be saved with the graphic plane. The number of the currently selected segment bitmap is shown beside the Number field. 2 Saving Vector Data The vector saving panel allows the user to save one vector layer from in-memory to a vector segment on a database file. The save panel is divided into three subareas, which are described in the following subtopics. When the desired vector layer to vector segment mapping has been chosen the ``Save'' button will save the vector layer but leave the save panel visible. The ``Save And Close'' button will save the requested vector layer, and pop the panel down. The ``New File'' action button is used to select a new database to which to save the vector data. 3 Vector Layers and Segments The ``Savable Vector Layers'' section of the Vector Save panel is used to select an in-memory vector layer to save to the disk file. It is a scrollable list of vector layers, and the selected vector layer to be saved is highlighted. The ``Database Vector Segments'' section of the Vector Save panel is used to select a vector segment on the database file to which to save the vector data. It is a scrollable list of vector segments, and the selected vector segment to which the vector data will be saved will appear highlighted. If the database file, to which the graphic plane will be saved, is a PCIDSK file, it is not necessary to select a vector segment. If no target bitmap segment has been selected, or the ``Number'' field of the Segment Information area has been cleared, a new vector segment will be created. 3 Segment Information The Segment Information area is used to modify the segment name and description, to be saved with the vector information. The number of the currently selected vector segment is shown beside the Number field. 2 Saving LUT Data The LUT (Lookup Table) saving panel allows the user to save one of the LUTs currently associated with an image plane in memory. The save panel is divided into three subareas, which are described in the following subtopics. When the desired image plane to LUT segment mapping has been chosen, the ``Save'' button will save the LUT but leave the save panel visible. The ``Save And Close'' button will save the requested LUT, and pop the panel down. The ``New File'' action button is used to select a new database to which to save the vector data. 3 Savable LUTs and LUT Segments The ``Savable LUTs'' section of the LUT Save panel is used to select an in-memory LUT to save to the disk file. It is a scrollable list of LUTs associated with image planes, and the selected LUT to be saved is highlighted. The ``Database LUT Segments'' section of the LUT Save panel is used to select an LUT segment on the database file to which to save the LUT. It is a scrollable list of LUT segments, and the selected segment to which the LUT will be saved will appear highlighted. If the disk file, to which the LUT will be saved, is a PCIDSK file, it is not necessary to select an LUT. If no target LUT segment has been selected, or the ``Number'' field of the Segment Information area has been cleared, a new LUT segment will be created. 3 Segment Information The Segment Information area is used to modify the segment name and description, to be saved with the vector information. The number of the currently selected vector segment is shown beside the Number field. 2 Saving PCT Data The Save PCT Panel is used to save the single in-memory PCT (Pseudo-Colour Table) to a database file. The ``Database PCT Segments'' section of the PCT Save panel is used to select a PCT segment on the database file to which to save the PCT. It is a scrollable list of PCT segments, and the PCT selected segment to which the PCT will be saved will appear highlighted. When saving to PCIDSK database files it is not necessary to select a PCT segment. If none are selected, or if the ``Number'' field is cleared, a new PCT segment will be created on the database. 1 Georeferencing Editor @index{Georeferencing Editor}{Projections!Georeferencing Editor} @keyword{GeoEdit Georeferencing Projections Geocoding} @alias{GeoEdit} The Georeferencing Editor (or GeoEdit) is a standard Works control for viewing and editing the georeferencing system and boundaries of data layers. The GeoEdit object comes in two forms. The first is the minimal form and contains only the controls for setting the georeferencing system (eg. UTM, Long/Lat), while the second form also includes the georeferenced boundaries of the region being described. There are also two modes for the GeoEdit control. In some places it is used in ``View Only'' mode, and none of the values may be changed by the user. Normally it is in ``Editable Mode'' and any of the values may be changed interactively. The georeferencing coordinate system is set by selecting the desired coordinate system from the option menu of possible systems. The currently available coordinate systems are: - Pixel: No georeferencing known. Measured in data pixels and lines. - UTM: Universal Transverse Mercator (zone optional). - Long/Lat: Geographic, or Longitude/Latitude. - Metre: Relative metres. World location unknown. - SPCS: State Plane Coordinate System in metres (zone required). - Other: Another unlisted projection (not for user selection). To the left of the option menu is a text field which contains the full georeferencing string currently in use. This includes the georeferencing coordinate system set on the option menu, plus a zone number and ellipsoid where applicable. The UTM and SPCS projections require a zone number and most georeferencing systems require an ellipsoid (earth model). The zone number is placed after the georeferencing system, and before the ellipsoid. The ellipsoid appears at the end of the georeferencing string, and is indicated by a numeric code such as ``E000'' (Clark 1866 / NAD27) or ``E012'' (WGS 1984). The default ellipsoid is ``E000''. After being entered by the user, the string is validated and reformatted. Note that changing the georeferencing system from one projection to another will not cause the bounding rectangle to be reprojected. Instead the corner values will be reinterpreted in the new georeferencing system. For a detailed list of possible georeferencing systems, ellipsoid codes, and zone codes, consult the projections help file. Note that it is not possible to set projections parameters for projections other than UTM, SPCS, or UPS from the GeoEdit object. Other projections must be applied to data using PACE programs before they are read into Works programs. Examples: "UTM 11 E012" "SPCS 1101 E000" "LONG/LAT E008" On GeoEdit controls that are used to define a region, there will appear four additional text fields. The first two are labelled ``Upper Left'' and define the horizontal and vertical position of the top left corner of the region. The other two are labelled ``Lower Right'' and define the lower right corner of the region being defined. The values entered in these fields are interpreted in the georeferencing units specified above. Geographic (Long/Lat) coordinates may be specified in Degrees, Minutes, Seconds form (ie. 152d00`00.00" E) or in decimal degrees (ie. -152.0). Note that the upper left corner specified is in fact the upper left corner of the upper left pixel for raster images, and the lower right corner is the lower right corner of the lower right pixel. See Also: {PROJ}Projections 1 HELP 2 ERRORS 3 Locked PCIDSK Channel The PCIDSK channel you have selected to save to is ``Write Locked''. You may use the PACE program UNLOCK to make the channel writable; however, you might want to consider why the channel was write locked. 3 Write Access Denied You do not have write permission on the file you attempted to save to. Please check to see if you own the file, and whether you have write permissions on the file. 3 Segment Too Small The vector segment you have tried to save to is too small to contain all the data. Please select ``Create New Segment'' on the vector save panel and try again. 3 Missing Help File The request help file corresponding to the requested help topic can not be found. Help files are normally found in /pci/hlp under names such as /pci/hlp/IWORKS.HLP. Check that /pci/hlp exists, that its contents are accessible to all users, and that the help file corresponding to the requested topic exists. The local directory is also searched for help files. 3 Trapped IMP Error An IMP Error has been trapped, possibly corrupting the application data. Proceed with caution. The Trapped IMP Error messages will include an IMP Error code, which will be translated into an IMP Error message if a proper PRM.PRM file is available in the local directory.