topic Re: Spot 5 Natural color in ArcGIS Spatial Analyst Questions

Spot 5 Natural color

MuhammadMubashir__Khan — Tue, 03 Mar 2015 16:02:19 GMT

I have 2 spot 5 satellite imagery ( 2.5 m) in Color Infrared and i would like to convert them to natural color.As Spot 5 images do not have blue Band Like Landsat.Can someone help me with the process in ArcGis.

Re: Spot 5 Natural color

JayantaPoddar — Tue, 03 Mar 2015 17:30:28 GMT

Hi Mubhashir,

You could try the following, and let me know.

say For SPOT imagery,

S1: Green band

S2: Red Band

S3: NIR Band

Use the following equations in Raster Calculator,

Red = S2
Green = (3 * S1 + S3)/4
Blue = (3 * S1 - S3)/4

Re: Spot 5 Natural color

MuhammadMubashir__Khan — Tue, 03 Mar 2015 19:54:59 GMT

I put the above Equations in raster claculator and now i amgetting a not executed error for a raster calculator.

Executing: RasterCalculator "Red = S2

Green = (3 * S1 + S3)/4

Blue = (3 * S1 - S3)/4" C:\Users\Mobii\Documents\ArcGIS\Default.gdb\rastercalc1

Start Time: Wed Mar 04 00:50:59 2015

Red = S2

Green = (3 * S1 + S3)/4

Blue = (3 * S1 - S3)/4

ERROR 000539: Parsing error IndentationError: unexpected indent (line 😎

Failed to execute (RasterCalculator).

Failed at Wed Mar 04 00:51:00 2015 (Elapsed Time: 1.00 seconds)

Re: Spot 5 Natural color

JayantaPoddar — Wed, 04 Mar 2015 18:49:58 GMT

Hi,

Did you use all the three equations in one go? You need to use Raster Calculator once for each band.

Moreover, in the expression, use only the right-hand side of the equations.

You need to create two rasters, viz., Green and Blue, as the output of the Raster Calculator.

And replace S1, S2 and S3 in the above equations with the Green band, Red band and NIR band of the SPOT data respectively. No need to use the Raster calculator for Red band.

Once the above bands are prepared, create composite bands using the new Blue, Green and Red bands.

http://resources.arcgis.com/en/help/main/10.2/index.html#//00170000009p000000

Then, use it in proper channels in symbology(Red band in Red Channel, Green band in Green channel and Blue band in Blue Channel) to get the natural colour composite.

Re: Spot 5 Natural color

MuhammadMubashir__Khan — Wed, 04 Mar 2015 20:16:36 GMT

OK I will try this and will let you know then.

Re: Spot 5 Natural color

CodyBenkelman — Wed, 04 Mar 2015 20:18:49 GMT

Yes, a reasonably good pseudo-true color image can be generated from color infrared imagery. We have an example on our resource center that refers specifically to SPOT imagery.

I'll be very brief in my reply, but let me know if you need further detail.

Create a Mosaic Dataset and be sure to use the SPOT 5 Raster Type when you add the images into the Mosaic.
Under Mosaic Dataset properties (ArcCatalog), go to the Functions tab, and add the Spectral Matrix function. This function will apply user-controlled weights to the available bands to generate a three-band output for viewing.

This topic in our Resource Center provides advice re: specific weights to apply to generate an apparent true color image from a color infrared SPOT image:

http://resources.arcgis.com/en/help/main/10.2/index.html#/Spectral_Conversion_function/009t00000057000000/

Let me know if you need further detail!

Cody Benkelman