Perception-based Histogram Equalization for tone mapping applications
Bibliographic record
Abstract
Due to the ever increasing commercial availability of High Dynamic Range (HDR) content and displays, backward compatibility of HDR content with Standard Dynamic Range displays is currently a topic of high importance. Over the years, a significant amount of Tone Mapping Operators (TMOs) have been proposed to adapt HDR content to the restricted capabilities of SDR displays. Among them, the Histogram Equalization (HE) is considered to provide good results for a wide set of images. However, the naïve application of HE results either in banding artifacts or noise amplification when the HDR image has large unified areas (i.e. sky). In order to differentiate relevant information from noise in a uniform background, or in dark areas, the authors proposed a ceiling function. Their method results in noise-free but dim images. In this paper we propose a novel ceiling function which is based on the Perceptual Quantizer (PQ) function. Our method uses as threshold the number of code-words that PQ assigns on a luminance range in the original HDR image and the corresponding number of code-words in the resulting SDR image. We limit the number of code-words on SDR to be equal or less than the HDR. The saved code-words during the ceiling operation are redistributed to increase the contrast as well as the brightness of the final image. Results shows that provided SDR images are noise-free and brighter than the one obtained with prior HE operators. Finally since the proposed method is a Global TMO, it is thereby of low complexity and suitable for real time applications.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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 teacher head, 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".