Image Fusion
The fusion operation allows combination of images with different spectral and spatial resolution keeping the radiometric information. A huge effort has been put in developing fusion methods that preserve the spectral information and increase detail information in the hybrid product produced by the fusion process. The available methods in TerraAmazon are:
IHS: Fusion of a low-resolution multi-band image with a high-resolution image using the IHS method. The IHS method consists on transforming the R, G and B bands of the multispectral image into IHS components, replacing the intensity component by the panchromatic image, and performing the inverse transformation to obtain a high spatial resolution multispectral image.
Principal Components Fusion: Fusion of a low-resolution multi-band image with a high-resolution image using the PCA (Principal components analysis) method. The PCA performs image fusion where the first principal component of the multi-spectral image is replaced by the histogram matched panchromatic imagery.
Wisper: Fusion of a low-resolution multi-band image with a high resolution image using the WiSpeR method.
Select PROCESSING → RASTER PROCESSING → FUSION in the main menu.
On the List of Layers select the raster layer with a lower resolution.
Optionally use Filter By Name field giving part of the layer name to help find the layer in the list.
Press the Next button to go to next step or the Cancel button to close the dialog.
On the List of Layers select the raster layer with a higher resolution.
Optionally use Filter By Name field giving part of the layer name to help find the layer in the list.
Press the Next button to go to next step.
Fusion parameters
Select the Type of fusion to be used and set the their specific parameters.For each fusion method the user has to set up parameters in high-resolution, low-resolution or wavelet tabs.
IHS
Select the raster band index to process from the high resolution raster.
Select the raster band index from the lower resolution raster for the red channel.
Select the raster band index from the lower resolution raster for the green channel.
Select the raster band index from the lower resolution raster for the blue channel.
PCA
Select the raster band index to process from the high resolution raster.
Select each raster band index from the lower resolution raster will be part of the process.
WISPER
Select the raster band index to process from the high resolution raster.
Set the sensor type for the selected band.
Select and set the sensor type to each band of the lower resolution raster.
Select the filter type (wavelet parameter).
Define the number of decomposition levels (wavelet parameter).
The common options for all methods are:
Select the interpolator method to be used: nearest neighbor, bilinear or cubic.
Crop rasters to overlap area. This is necessary if the input rasters has different extents.
Press the Next button.
Output information
Raster Info - First
press
and inform the folder where the resulting file will be saved.
Name - inform the raster name.
Extra Parameters - if there are some.
Press the Finish button to save the resulting fused raster.