Services
Remote Sensing Help: Clipping/Subsetting an Image
When using the Clipping/Subsetting tool, there are a couple of options to create a subset. The output image can be any supported Geogateway compatible data type and does not need to be a PIX file format. There is also the option to create file subsets by entering coordinates for your subset or you can use a visual clipping method using the bounding outline in the Clip File panel preview window.
Start Geomatica.
Click once on the Focus icon.
From the toolbar, select Tools -- Clipping/Subsetting....
The Clipping/Subset screen will appear.
If your image to be subsetted is not displayed, click on the Browse button and locate the image. The image will appear in the preview screen and all the image bands and segments as well.
Now you can subset the image using four options as outlined below.
User-entered Co-ordinates: You can subset based on the Co-ordinate type which includes Raster Extents, Geocoded Extents, Long/Lat Extents, Raster offset/size and Geocoded offset/size. You can manually enter the co-ordinates or visually subset by dragging the corner of the preview image to the desired size as can be viewed below.
Select a File: If you want to subset based on another file, simply enter the filename in the blank space provided.
Select a Clip Layer: This would be an Intersecting layer to define the bounds of a subset. The Select a Clip Layer method works the same way as the Select a file method.
Select a Named Region: You can use the bounds of a Named Region to define your subset clip. You must have at least one Named Region in your source data to use this method. Named Regions can only be saved in Geomatica Project (GPR) files.
Once the desired size is selected, click on the bands that will be transferred into the subsetted image, enter a name for the output file and the format, as shown below.
Click on the OK button to perform the subsetting operation.
