Advanced Import allows you to import images and provides useful settings to change reference file, coordinate system, colour channel management, DEM schema, adjust image size and extents and even mosaic. It is also useful for quickly cropping large sized images to a specific geographic area which may have initially required a long load time. In this exercise, you’ll import two images of different formats, image sizes, and coordinate systems and then mosaic them together.
1.On the Geographic Imager panel, click the Advanced Import button.
2.On the Advanced Import dialog box, choose GeoTIFF/BigTIFF/TIFF from the Format drop-down list and click the Add Image Source button.
3.Navigate to the Tutorial Data folder, choose boston-east.tif, and click Open. If necessary, click OK to close the message box that warns about transparency and layer effects.
Information about boston-east.tif is displayed in the Image Sources list and shows that it has a Massachusetts Mainland Zone coordinate system and an 800 x 800 pixel image dimension.
4.Choose ECW from the Format drop-down list and click the Add Image Source button. (Note: ECW is not currently available on Apple Silicon machines)
5.Navigate to the tutorial data folder, choose boston-west.ecw, and click Open.
Information about boston-west.ecw is displayed in the list and shows that it has no coordinate system and a 650 x 650 pixel image dimension. You’ll use the Advanced Import options to make the images compatible so that they can be used in a mosaic.
6.Double-click the boston-west.ecw image source. In the Georeferencing section, click the Same As check box.
Only boston-east.tif is available in the coordinate system drop-down list because it is the only other file available in the file list. The coordinate system is updated to Massachusetts Mainland Zone in the file list for boston-west.ecw. Next, you’ll change the image dimensions for the GeoTIFF image by entering a resample value.
8.Double-click the boston-east.tif image source. In the Image Extents section, click the Resample button to open the Resample Image dialog box.
9.Change the Width to 650 pixels. The Keep Aspect Ratio option ensures the height is also 650 pixels.
10. Click OK.
11. The Dimensions column values update to reflect the resample size that you just entered.
Lastly, you’ll setup the mosaic option so that the files can be mosaicked together.
12. At the bottom of the dialog box, click the Mosaic all files to the destination document check box.
The boston-east.tif file is shown in the list and will be the destination document for the mosaic. Make sure the other settings match the above image.
13. Click OK to complete the Advanced Import process.
The two image formats are now mosaicked together to create one seamless image. This is a similar result to a workflow that would have required you to open the images separately, adjust the coordinate system, change the image size, and then create a mosaic. See more about Mosaic features.
In the Layers panel, notice that there is just one layer after the mosaic opertaion. This happened because you set the Layer Organization in the Advanced Import dialog box to Merge all layers.