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Geographic Imager: Create shaded relief from a DEM

With Geographic Imager 3.x, you can import DEM files to Adobe Photoshop and can create shaded relief images.

step 12: Shaded relief image completed

There are two methods to achieve this:

Method 1: Run the pre-made JavaScript and apply it to all images

After opening your DEM image, choose File > Scripts > Browse… and select Shaded Relief.jsx from the SampleScripts folder inside the Geographic Imager Tutorial folder. It will generate the shaded relief image for the opened DEM image based on the settings in the JavaScript file.

 

Method 2: Create shaded relief images manually

We’ll use the DEM file Rocky Mountains.dem available in the Geographic Imager Tutorial folder for this demonstration.

1) Open the Rocky Mountains.dem image from the Geographic Imager tutorial folder. Geographic Imager automatically detects it as a DEM file and provides the option to select the DEM image import method. For this demonstration, choose Auto-Stretched from the Select Schema drop-down list.

Step 1: Import DEM file option

The imported DEM is opened in black and white. Take a look at the header of the image (or tab of the image file). Notice that it displays “Gray/16”. This indicates that the image is in the 16 Bits/Channel Grayscale mode.

step 1: Imported DEM image

2) Now, change the image mode from 16 Bits/Channel Grayscale to 8 Bits/Channel RGB. From the top menu bar, choose Image > Mode and then 8 Bits/Channel. Once again, go to Image > Mode, this time choose RGB Color.

step 2: Changing the color mode

Once completed, take a look at the image header again (or file tab). Now “RGB/8” is indicated in the header, meaning that the image is now in the 8 Bits/Channel RGB color mode.

step 2: Color mode changed

3) Select the entire canvas (use the Rectangular Marquee Tool) and copy the selected area to the clipboard (Edit > Copy).

step 3: Select the entire canvas

4) Open the Channels panel (Window > Channels) and add one Alpha channel by clicking the Create new channel button at the bottom of the panel or go to the panel option menu and choose New Channel. Leave the channel name as “Alpha 1”.

step 4: create a new channel

5) Select the “Alpha 1” in the Channels panel and fill it in white using the Paint Bucket Tool.

step 5: Filling Alpha channel

6) In step 3 we copied the selected area (the entire canvas) to the clipboard, now we’re going to paste it to the new channel. Select “Alpha 1” in the Channels panel, and paste it (Edit > Paste). You can see that the same image is displayed for all the channels when the copied area is successfully pasted. Make the Alpha 1 channel invisible and make sure the RGB channels are visible.

step 6: pasted canvas

7) Deselect the area (Select > Deselect from the top menu bar).

step 7: deselected area

8) In the Layers panel (Window > Layers), create a new layer named Bump map. Change the Blending mode to Overlay. step 8: New Layer "Bump map"

9) Using the Paint Bucket Tool again, fill the new “Bump map” layer with white.

step 9: fill white

10) From the menu bar, choose Filter > Render > Lighting Effects…

step 10: Menu Filter > REnder > Lighting Effects ...

11) Adjust the settings in the Lighting Effects dialog window.

step 11: adjusting the light effect

12) The shaded relief image is completed! You can use this image to overlay with other georeferenced images with Geographic Imager or with vector datasets with MAPublisher.

step 12: Shaded relief image completed


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