Just Noticeable Quantization Levels For High Dynamic Range Images

Sozer, Sevim Begum
Koz, Alper
Akyüz, Ahmet Oğuz
Zerman, Emin
Valenzise, Giuseppe
Dufaux, Frederic
Just noticeable quantization levels, which are conventionally used in picture coding, have been mainly developed for standard 8-bit images and low dynamic range (LDR) typical screens. The quantization levels however have not been adapted yet for high dynamic range (HDR) imaging and its accompanied HDR displays, which can reach up to a peak luminance of 4000 cd/m 2 . This study proposes an experimental methodology on HDR displays to determine just noticeable quantization levels for discrete cosine transform (DCT) coefficients on high luminance images. In the first stage of the proposed method, the quantization noise patterns for different DCT frequencies at different mean luminances are rendered by predicting the LED and LCD values of the two layer HDR display. Then, a two alternative forced choice based psychovisual experimental procedure using geometric search and QUEST methodology is realized by randomly presenting the rendered quantization noise at different amplitudes to the subjects in order to determine the just noticeable levels. The experiments are performed over 3 subjects for 30 different frequencies of 8×8 DCT patterns at mean luminances of 100 cd/m 2 and 1000 cd/m 2 . The results are interpreted with respect to frequency and luminance changes and from the point of utilized methodology, namely geometric search and QUEST.


Privacy protection of tone-mapped HDR images using false colours
ÇİFTÇİ, Serdar; Akyüz, Ahmet Oğuz; PİNHEİRO, Antonio M. G.; Ebrahimi, Touradj (2017-12-01)
High dynamic range (HDR) imaging has been developed for improved visual representation by capturing a wide range of luminance values. Owing to its properties, HDR content might lead to a larger privacy intrusion, requiring new methods for privacy protection. Previously, false colours were proved to be effective for assuring privacy protection for low dynamic range (LDR) images. In this work, the reliability of false colours when used for privacy protection of HDR images represented by tone-mapping operators...
Ghost Removal in High Dynamic Range Images
Khan, Erum Arif; Akyüz, Ahmet Oğuz; Reinhard, Erik (2006-10-11)
High dynamic range images may be created by capturing multiple images of a scene with varying exposures. Images created in this manner are prone to ghosting artifacts, which appear if there is movement in the scene at the time of capture. This paper describes a novel approach to removing ghosting artifacts from high dynamic range images, without the need for explicit object detection and motion estimation. Weights are computed iteratively and then applied to pixels to determine their contribution to the fin...
An Experimental Method to Determine Quantization Levels for High Luminance Patterns
Sözer, Sevim Begüm; Koz, Alper; Akyüz, Ahmet Oğuz; Zerman, Emin; Valenzise, Giuseppe; Dufaux, Frederic (2020-10-05)
The quantization levels, which forms an important basis for video coding, are mainly determined for 8-bit image representation and for low dynamic range (LDR) typical displays with a luminance level of 100-500 cd/ m 2 . The quantization levels have not been studied until now for high luminance patterns and high dynamic range (HDR) displays, which can reach up to 4000 cd/m 2 . In this study, an HDR display based perceptual experimental method is proposed in order to determine just noticeable quantization lev...
Automatic saturation correction for dynamic range management algorithms
Artusi, Alessandro; POULİ, Tania; BANTERLE, Francesco; Akyüz, Ahmet Oğuz (2018-04-01)
High dynamic range (HDR) images require tone reproduction to match the range of values to the capabilities of a display. For computational reasons and given the absence of fully calibrated imagery, rudimentary color reproduction is often added as a post-processing step rather than integrated into tone reproduction algorithms. In the general case, this currently requires manual parameter tuning, and can be automated only for some global tone reproduction operators by inferring parameters from the tone curve....
Directional coding of backward compatible high dynamic range (HDR) image coding residues
Feyiz, Kutan; Kamışlı, Fatih; Department of Electrical and Electronics Engineering (2018)
High dynamic range (HDR) image and video formats are proposed to overcome limitations of widely accepted standard 8-bit low dynamic range (LDR) image and video representations. The main aim of these formats is to encode the whole luminance range of real world scenes which changes from extreme darkness ( 10 − 6 cd/ m 2 ) to bright sunshine ( 10 8 cd/ m 2 ), and to generate and store such scenes independent from the display technology. To achieve a successful transition from LDR to HDR technology, backward ...
Citation Formats
S. B. Sozer, A. Koz, A. O. Akyüz, E. Zerman, G. Valenzise, and F. Dufaux, “Just Noticeable Quantization Levels For High Dynamic Range Images,” 2020, Accessed: 00, 2021. [Online]. Available: https://ieeexplore.ieee.org/document/9190931/.