Brovey
Normalizes the panchromatic detail by a synthetic multispectral intensity and injects that detail into each band.
Fi = MSi × PAN / ΣwjMSj
Best used when: high visual sharpness is desired and some spectral distortion is acceptable.
Pansharpening
Fuse the high spatial detail of a panchromatic image with the spectral content of a lower-resolution multispectral image.
Remote Sensing CoreEnd-User DocumentationTheory + Formula + Parameters1. What This Feature Does
Fuse the high spatial detail of a panchromatic image with the spectral content of a lower-resolution multispectral image.
Cloud workflow: choose data → configure the scientific method → run → review the resulting layer/report. No programming is required.
2. Recommended Workflow
Select multispectral and higher-resolution panchromatic rasters.
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Select multispectral bands and PAN band.
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Choose a pansharpening algorithm.
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Choose resampling/statistics/detail settings.
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Review both sharpness and spectral fidelity.
3. Theory, Methods & Equations
IHS
Transforms three RGB bands to Intensity-Hue-Saturation, replaces/matches intensity using PAN, then converts back.
I ≈ (R+G+B)/3
Best used when: exactly three display bands are being sharpened.
Gram-Schmidt
Creates a synthetic PAN from multispectral bands, orthogonalizes components, replaces the first component with matched PAN, and reconstructs bands.
Best used when: spectral preservation across multiple bands is important.
PCA Pansharpening
Replaces the first principal component with a histogram/statistics-matched PAN, then applies the inverse PCA transform.
C = (1/(n−1))XTX
C vk=λkvk
Best used when: multiband covariance structure is useful for detail injection.
À trous Wavelet
Decomposes PAN into low-frequency and spatial-detail components without downsampling, then injects detail into multispectral bands.
Detaill = Al−1 − Al
Best used when: multi-scale spatial detail needs controlled injection.
4. Input Data
| Input | Type | Requirement | Description |
|---|---|---|---|
| Multispectral Raster | raster | Required for selected method | Multiband raster providing the spectral information. |
| Panchromatic Raster | raster | Required for selected method | Higher-resolution raster providing spatial detail. |
5. Parameters Available in the Application
| Parameter | Default | Choices / Range | How to Use It |
|---|---|---|---|
| Pansharpening Algorithm | — | Brovey, IHS (Intensity-Hue-Saturation), Gram-Schmidt, PCA Pansharpening, Wavelet (à trous) | Select the pansharpening algorithm first. Only relevant parameters are shown. |
| Select Input Bands | — | — | Multispectral bands to sharpen. Default is All bands. IHS requires exactly three selected bands. Shown for: brovey, ihs, gram_schmidt, pca, wavelet |
| Panchromatic Band | 1 | 1 to — | Shown for: brovey, ihs, gram_schmidt, pca, wavelet |
| Multispectral Resampling | bilinear | nearest, bilinear, cubic, lanczos | Shown for: brovey, ihs, gram_schmidt, pca, wavelet |
| Match PAN Statistics | On | — | Match PAN mean and standard deviation to the multispectral intensity before spatial-detail injection. Shown for: brovey, ihs, gram_schmidt, wavelet |
| Synthetic PAN Weights | — | — | Optional weight per selected multispectral band. Leave empty for equal weights. Shown for: brovey, gram_schmidt |
| PCA Fitting Samples | 200000 | 1000 to 5000000 | Shown for: pca |
| Wavelet Levels | 2 | 1 to 6 | Number of undecimated à trous B3-spline decomposition levels. Shown for: wavelet |
| Wavelet Detail Gain | 1.0 | 0.0 to 5.0 | Shown for: wavelet |
| Random State | 42 | — | Shown for: pca |
6. Output & Interpretation
The result should be interpreted according to the selected method and the physical meaning of the input data. Preserve source units, coordinate reference information, NoData meaning, acquisition date, and preprocessing level when comparing results.
Scientific interpretation: an algorithm can produce a numerically valid result even when the input data are unsuitable. Always check masks, units, sensor characteristics, spatial resolution and reference data.
Important: A sharper image is not automatically more radiometrically accurate. Check spectral indices after pansharpening if quantitative spectral fidelity matters.
7. Best Practices
- Use analysis-ready inputs and remove invalid/cloud/noise artifacts that are not part of the target phenomenon.
- Choose parameters from the physical scale of the data, not only from visual appearance.
- Keep categorical and continuous rasters conceptually separate when selecting interpolation/resampling methods.
- Compare the result with the source image and independent reference information.
- Document the settings used when results will be compared across dates, sensors or study areas.