Requirements
Any image can be cropped using GeoCrop. However, only georeferenced images will enable certain options in the GeoCrop dialog box. GeoCrop can't be used on images without georeferencing.
To use the Crop to Coordinate System Envelope option, the current image must be georeferenced.
To use the Crop to Another Document option, at least one other georeferenced document must be opened.
GeoCrop Dialog Box
With an opened image, click the GeoCrop button in the Geographic Imager panel to open the GeoCrop dialog box.
GeoCrop button
To GeoCrop an image, use one of the following crop options:
Manual Crop
Manual GeoCrop is the quickest and simplest method to crop an image. In the preview image, click and drag to draw a selection marquee area—the preview will immediately crop. Click the Undo buttonThe area outside of the crop area is shaded in gray. Use the cursor coordinates below the preview image to more accurately crop an image. The crop area can be only as large as the extent of the image and only one crop area can be defined at a time.
You can also use the Adobe Photoshop Crop Tool which is fully supported and maintains georeferencing.
Crop By Extents
To crop an area by extents, click the Crop By Extents button. Begin by setting the coordinate system (geodetic or projected) and if necessary, the coordinate format (only for geodetic coordinate systems). Settings and units in this dialog box change depending on whether a geodetic or projected coordinate system is used.
When the coordinate system is geodetic (e.g. WGS 84), specify the Latitude and Longitude values in the Minimum and Maximum boxes to define a precise selection area. Several formats are available in the Format drop-down, including: Decimal Degrees, Delimited Degrees Minutes Seconds, Degrees.Minutes, Degrees.MinutesSeconds, Packed DMS with decimal point, and Packed DMS. The preview image updates and draws the selection area using the coordinates specified.
To use a specified coordinate system, select Specified Coordinate System from the Use drop-down and click the coordinate system link to browse for one. When using a projected coordinate system (e.g. Winkel-Tripel), specify the X and Y values in the Minimum and Maximum boxes to define a precise selection area. The units indicated will be the same as the specified coordinate system (e.g. meters). The preview image updates and draws the selection area using the coordinates specified.
Crop By Position
To crop an area by position, click the Crop By Position button. Use this feature to crop an area of the image based on the dimension from a specific base point. Begin by setting the coordinate system (geodetic or projected) and if necessary, the coordinate format (only for geodetic coordinate systems). Settings and units in this dialog box change depending on whether a geodetic or projected coordinate system is used.
In the Point drop-down, choose a position for the base point. Under Base Point, specify the Latitude and Longitude values (or X and Y if using a projected coordinate system) of the point of which the select area will be based on. This position defines where the select area is created relative to the base point. The diagram below explains base point positioning.
Under Dimensions, specify Width and Height values (in the same units as the base point) of which the select area dimensions will be drawn to. If needed, click the Constrain dimensions check box to keep both dimension values the same (create a square select area). If a specified coordinate system is projected, it is possible to change the dimension units. Click the Change Units button and choose a new measurement unit. The preview image updates and draws the selection area using the base point and dimensions specified.
Crop To Another Document's Extents
Select the image area using the extents of another open document. Click the Crop To Another Document's Extents button and choose the document from the drop-down. The other document must have extents that intersect with the existing image area.
Crop By File Vector Extents
Use this feature to crop an area based on the geographic extents of a vector file. Click the Select By Vector File Extents button to select a vector dataset. Choose from a variety of vector formats including shapefiles, KML/KMZ, GPX, and DWG. Note that this does not select an area to the boundary defined by the vector, only a rectangular shape defined by its geographic extents.
Esri formats such as geodatabases (GDB, MDB, MXD) and text formats (TXT, CSV, XLS) are not supported.
Crop To Coordinate System Envelope
Crop the image area using the envelope of a coordinate system to define the selection area of the current image. Click the Select Area By Coordinate System Envelope button to choose a coordinate system. The preview image updates and draws the selected area using the extents of the coordinate system envelope specified. It is important to use a coordinate system envelope that falls within the extents of the current image. If only a portion of the envelope falls within the extents, it will still be selected and cropped. If a coordinate system envelope is outside of the image’s extents, it will fail to select and a warning will appear.
Preferences
These preferences affect format and precision when cropping images.
Lat/Long Format |
Set the default of how latitude and longitude values are displayed. |
Geodetic Precision |
Set how many decimals are displayed for geodetic coordinate systems (latitude and longitude values). |
Projected Precision |
Set how many decimals are displayed for projected coordinate system values (X and Y values). |
Coordinate Display |
Set which coordinates to display when the cursor hovers over the preview image. These coordinates are displayed below the preview image in the Select Area dialog box. |
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