Learning Foveated Reconstruction to Preserve Perceived Image Statistics

Foveated image reconstruction recovers full image from a sparse set of samples distributed according to the human visual system's retinal sensitivity that rapidly drops with eccentricity. Recently, the use of Generative Adversarial Networks was shown to be a promising solution for such a task as they can successfully hallucinate missing image information. Like for other supervised learning approaches, also for this one, the definition of the loss function and training strategy heavily influences the output quality. In this work, we pose the question of how to efficiently guide the training of foveated reconstruction techniques such that they are fully aware of the human visual system's capabilities and limitations, and therefore, reconstruct visually important image features. Due to the nature of GAN-based solutions, we concentrate on the human's sensitivity to hallucination for different input sample densities. We present new psychophysical experiments, a dataset, and a procedure for training foveated image reconstruction. The strategy provides flexibility to the generator network by penalizing only perceptually important deviations in the output. As a result, the method aims to preserve perceived image statistics rather than natural image statistics. We evaluate our strategy and compare it to alternative solutions using a newly trained objective metric and user experiments

Design of a Tone Mapping Operator for High Dynamic Range Images based upon Psychophysical Evaluation and Preference Mapping

A tone mapping algorithm for displaying high contrast scenes was designed on the basis of the results of experimental tests using human subjects. Systematic perceptual evaluation of several existing tone mapping techniques revealed that the most “natural” appearance was determined by the presence in the output image of detailed scenery features often made visible by limiting contrast and by properly reproducing brightness. Taking these results into account, we developed a system to produce images close to the ideal preference point for high dynamic range input image data. Of the algorithms that we tested, only the Retinex algorithm was capable of retrieving detailed scene features hidden in high luminance areas while still preserving a good contrast level. This paper presents changes made to Retinex algorithm for processing high dynamic range images, and a further integration of the Retinex with specialized tone mapping algorithms that enables the production of images that appear as similar as possible to the viewer’s perception of actual scenes

Dry diet influenced growth, size variability, condition and body deformities in juvenile crucian carp, Carassius carassius L., reared under controlled conditions.

Abstract. The growth, size variability, condition coefficient and percentage of fish with external deformities were compared in juvenile crucian carp (initially 31 mm TL and 0.36 g BW) which were fed intensively four starters only for 120 days at 25°C. The best weight gain was achieved by fish fed an experimental carp diet with the lowest fat content (7.4%) and a commercial diet for eel containing 15.9% fat (4.33 and 4.15 g BW, respectively). In contrast to the experimental diets, both commercial diets produced fish with high condition coefficient values and a very high (37.2 or 62.7%) percentage of individuals with different external deformities. Size variability did increase over the course of the experiment except in the fish fed the high-energy diet for eel. Survival rates ranged between 96.5 and 99.5%. Our results indicate that juvenile crucian carp can be successfully reared exclusively on dry diets but not the commercial ones for eel or carp used in the present experiment

Manipulating Refractive and Reflective Binocular Disparity

Presenting stereoscopic content on 3D displays is a challenging task, usually requiring manual adjustments. A number of techniques have been developed to aid this process, but they account for binocular disparity of surfaces that are diffuse and opaque only. However, combinations of transparent as well as specular materials are common in the real and virtual worlds, and pose a significant problem. For example, excessive disparities can be created which cannot be fused by the observer. Also, multiple stereo interpretations become possible, e. g., for glass, that both reflects and refracts, which may confuse the observer and result in poor 3D experience. In this work, we propose an efficient method for analyzing and controlling disparities in computer-generated images of such scenes where surface positions and a layer decomposition are available. Instead of assuming a single per-pixel disparity value, we estimate all possibly perceived disparities at each image location. Based on this representation, we define an optimization to find the best per-pixel camera parameters, assuring that all disparities can be easily fused by a human. A preliminary perceptual study indicates, that our approach combines comfortable viewing with realistic depiction of typical specular scenes

Comparing the Clinical Utility of the Infant Developmental Inventory With the Ages and Stages Questionnaire at 9-Month Well-Child Visits

Objective: The purpose of our study was to compare the clinical utility of administering 2 recommended developmental screening instruments, the Infant Developmental Inventory (IDI) and the Ages and Stages Questionnaire (ASQ), at 9-month well-child visits in paper format. Methods: Outcomes of the 2 screens, including correct completion and interpretation by clinician, time of visit, and screen outcome were compared. Results: Out of 33 children administered the ASQ and with documented scores, 12 (36.4%) did not receive passing scores, while 5 (12.2%) of the 41 children administered the IDI did not receive passing scores ( P = .014). Out of 41 IDI screens, 12 (29.3%) were completed incorrectly, while there were no ASQ screens completed incorrectly ( P < .001) by caregivers. Conclusion: In our pilot study, the ASQ is more often completed correctly by caregivers and identifies more children at risk for delay as compared with the IDI. Additional larger scale studies are needed to evaluate the usefulness of developmental screening tools when used within primary care practice