Denoising Hyperspectral Imagery Using Principal Component Analysis and Block-Matching 4D Filtering
Bibliographic record
Abstract
In this article, we propose a new method for denoising hyperspectral imagery. Hyperspectral imagery normally contains a small amount of noise, which can hardly be seen by human eyes thanks to its relatively high signal-to-noise ratio. However, in many remote sensing applications, this amount of noise is still troublesome. In this study, we first perform principal component analysis (PCA) to the hyperspectral data cube to be denoised in order to separate the fine features from the noise in the hyperspectral data cube. Because the first few PCA output channels contain the majority of information in the hyperspectral data cube, we do not denoise these PCA output channel images. We use the block-matching 4D (BM4D) filtering to reduce the noise in the remaining low-energy noisy PCA output channel images. Finally, an inverse PCA transform is performed in order to obtain the denoised hyperspectral data cube. Experimental results show that our proposed method in this work is very competitive when compared with existing methods for hyperspectral imagery denoising.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".