Javier Portilla | CSIC (Consejo Superior de Investigaciones Científicas-Spanish National Research Council) (original) (raw)

Uploads

Papers by Javier Portilla

Research paper thumbnail of Procedimiento de restauración de imágenes afectadas por imperfecciones, dispositivo para llevarlo a cabo y sus aplicaciones

Research paper thumbnail of Texture Synthesis-By-Analysis Based on a Multiscale Early

IEEE Trans. on Aerospace …, 1993

Page 1. Title: “TEXTURE SYNTHESIS-BY-ANALYSIS BASED ON A MULTISCALE EARLY-VISION MODEL”. Authors:... more Page 1. Title: “TEXTURE SYNTHESIS-BY-ANALYSIS BASED ON A MULTISCALE EARLY-VISION MODEL”. Authors: Javier Portilla, Rafael Navarro, Oscar Nestares and Antonio Tabernero*. Address: Instituto de Optica (CSIC). Serrano 121. 28006 Madrid. Spain. ...

Research paper thumbnail of Textures synthesis-by-analysis based on a multiscale early-vision model

Abstract. A new texture synthesis-by-analysis method, applying a visu-ally based approach that ha... more Abstract. A new texture synthesis-by-analysis method, applying a visu-ally based approach that has some important advantages over more traditional texture modeling and synthesis techniques is introduced. The basis of the method is to encode the textural information by sampling ...

Research paper thumbnail of Representación local multiescala de imágenes: Modelado y síntesis de texturas

Research paper thumbnail of Controlled Feature Adjustment for Image Processing and Synthesis

2020 IEEE 22nd International Workshop on Multimedia Signal Processing (MMSP)

Research paper thumbnail of Comparing optical to digital metrics: what is the optimal defocus in a rotationally summetric system?

2017 IEEE International Conference on Image Processing, China National Convention Center in Beiji... more 2017 IEEE International Conference on Image Processing, China National Convention Center in Beijing, China, 17-20 September 2017. -- http://2017.ieeeicip.org/Peer Reviewe

Research paper thumbnail of Deterministic Feature Decoupling by Surfing Invariance Manifolds

ICASSP 2020 - 2020 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2020

Research paper thumbnail of Efficient PSF field estimation, tracing few rays, in axially symmetric optical systems

Imaging and Applied Optics 2019 (COSI, IS, MATH, pcAOP), 2019

Proceedings Imaging and Applied Optics 2019, Munich, Germany, 24–27 June 201

Research paper thumbnail of Hybrid digital-optical imaging design for reducing surface asphericity cost while keeping high performance

Computational Optics II, 2018

Research paper thumbnail of Computational estimation of point-spread-function field in axially symmetric optical systems

Journal of Modern Optics, 2020

Research paper thumbnail of Spectral pre-adaptation for two-step arbitrary-shape-support image restoration

2017 IEEE International Conference on Image Processing (ICIP), 2017

Research paper thumbnail of Avoiding tracing too many rays for characterizing an axially symmetric optical system

Optical Design and Fabrication 2017 (Freeform, IODC, OFT), 2017

Research paper thumbnail of A perceptual Bayesian estimation framework and its application to image denoising

2006 14th European Signal Processing Conference, 2006

We present a generic Bayesian framework for signal estimation that incorporates into the cost fun... more We present a generic Bayesian framework for signal estimation that incorporates into the cost function a perceptual metric. We apply this framework to image denoising, considering additive noise of known density. Under certain assumptions on the way local differences in visual responses add up into a global perceptual distance, we obtain analytical solutions that exhibit interesting theoretical properties. We demonstrate through simulations, using an infomax nonlinear perceptual mapping of the input and a local Gaussian model, that in the absence of a prior the new solutions provide a significant improvement on the visual quality of the estimation. Furthermore, they also improve in Mean Square Error terms w.r.t. their non-perceptual counterparts.

Research paper thumbnail of Simulating real-world scenes viewed through ophthalmic lenses

Journal of the Optical Society of America A, 2017

Research paper thumbnail of Dispersion kernels for water wave simulation

ACM Transactions on Graphics, 2016

We propose a method to simulate the rich, scale-dependent dynamics of water waves. Our method pre... more We propose a method to simulate the rich, scale-dependent dynamics of water waves. Our method preserves the dispersion properties of real waves, yet it supports interactions with obstacles and is computationally efficient. Fundamentally, it computes wave accelerations by way of applying a dispersion kernel as a spatially variant filter, which we are able to compute efficiently using two core technical contributions. First, we design novel, accurate, and compact pyramid kernels which compensate for low-frequency truncation errors. Second, we design a shadowed convolution operation that efficiently accounts for obstacle interactions by modulating the application of the dispersion kernel. We demonstrate a wide range of behaviors, which include capillary waves, gravity waves, and interactions with static and dynamic obstacles, all from within a single simulation.

Research paper thumbnail of The relationship between dioptric power and magnification in progressive addition lenses

Ophthalmic and Physiological Optics, 2016

Research paper thumbnail of Full blind Bayesian denoising using scale mix-tures of Gaussians in the wavelet domain

Research paper thumbnail of Image Denoising using Scale Mixtures of

Research paper thumbnail of Title: "TEXTURE SYNTHESIS-BY-ANALYSIS BASED ON A MULTISCALE EARLYVISION MODEL

This paper introduces a new texture synthesis-by-analysis method, applying a visual-based approac... more This paper introduces a new texture synthesis-by-analysis method, applying a visual-based approach which has some important advantages over more traditional texture modeling and synthesis techniques. The basis of the method is to encode the textural information by sampling both the power spectrum and the histogram of homogeneously textured images. The spectrum is sampled in a log-polar grid by using a pyramid Gabor scheme. The input image is split into a set of 16 Gabor channels (using four spatial frequency levels and four orientations), plus a low-pass residual (LPR). The energy and equivalent bandwidths of each channel, as well as the LPR power spectrum and the histogram, are measured and the latter two are compressed. The synthesis process consists of generating 16 Gabor filtered independent noise signals with spectral centers equal to those of the Gabor filters, whose energy and equivalent bandwidths are calculated in order to reproduce the measured values. These band-pass sign...

Research paper thumbnail of Two-level adaptive denoising using Gaussian scale mixtures in overcomplete oriented pyramids

IEEE International Conference on Image Processing 2005, 2005

Research paper thumbnail of Procedimiento de restauración de imágenes afectadas por imperfecciones, dispositivo para llevarlo a cabo y sus aplicaciones

Research paper thumbnail of Texture Synthesis-By-Analysis Based on a Multiscale Early

IEEE Trans. on Aerospace …, 1993

Page 1. Title: “TEXTURE SYNTHESIS-BY-ANALYSIS BASED ON A MULTISCALE EARLY-VISION MODEL”. Authors:... more Page 1. Title: “TEXTURE SYNTHESIS-BY-ANALYSIS BASED ON A MULTISCALE EARLY-VISION MODEL”. Authors: Javier Portilla, Rafael Navarro, Oscar Nestares and Antonio Tabernero*. Address: Instituto de Optica (CSIC). Serrano 121. 28006 Madrid. Spain. ...

Research paper thumbnail of Textures synthesis-by-analysis based on a multiscale early-vision model

Abstract. A new texture synthesis-by-analysis method, applying a visu-ally based approach that ha... more Abstract. A new texture synthesis-by-analysis method, applying a visu-ally based approach that has some important advantages over more traditional texture modeling and synthesis techniques is introduced. The basis of the method is to encode the textural information by sampling ...

Research paper thumbnail of Representación local multiescala de imágenes: Modelado y síntesis de texturas

Research paper thumbnail of Controlled Feature Adjustment for Image Processing and Synthesis

2020 IEEE 22nd International Workshop on Multimedia Signal Processing (MMSP)

Research paper thumbnail of Comparing optical to digital metrics: what is the optimal defocus in a rotationally summetric system?

2017 IEEE International Conference on Image Processing, China National Convention Center in Beiji... more 2017 IEEE International Conference on Image Processing, China National Convention Center in Beijing, China, 17-20 September 2017. -- http://2017.ieeeicip.org/Peer Reviewe

Research paper thumbnail of Deterministic Feature Decoupling by Surfing Invariance Manifolds

ICASSP 2020 - 2020 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2020

Research paper thumbnail of Efficient PSF field estimation, tracing few rays, in axially symmetric optical systems

Imaging and Applied Optics 2019 (COSI, IS, MATH, pcAOP), 2019

Proceedings Imaging and Applied Optics 2019, Munich, Germany, 24–27 June 201

Research paper thumbnail of Hybrid digital-optical imaging design for reducing surface asphericity cost while keeping high performance

Computational Optics II, 2018

Research paper thumbnail of Computational estimation of point-spread-function field in axially symmetric optical systems

Journal of Modern Optics, 2020

Research paper thumbnail of Spectral pre-adaptation for two-step arbitrary-shape-support image restoration

2017 IEEE International Conference on Image Processing (ICIP), 2017

Research paper thumbnail of Avoiding tracing too many rays for characterizing an axially symmetric optical system

Optical Design and Fabrication 2017 (Freeform, IODC, OFT), 2017

Research paper thumbnail of A perceptual Bayesian estimation framework and its application to image denoising

2006 14th European Signal Processing Conference, 2006

We present a generic Bayesian framework for signal estimation that incorporates into the cost fun... more We present a generic Bayesian framework for signal estimation that incorporates into the cost function a perceptual metric. We apply this framework to image denoising, considering additive noise of known density. Under certain assumptions on the way local differences in visual responses add up into a global perceptual distance, we obtain analytical solutions that exhibit interesting theoretical properties. We demonstrate through simulations, using an infomax nonlinear perceptual mapping of the input and a local Gaussian model, that in the absence of a prior the new solutions provide a significant improvement on the visual quality of the estimation. Furthermore, they also improve in Mean Square Error terms w.r.t. their non-perceptual counterparts.

Research paper thumbnail of Simulating real-world scenes viewed through ophthalmic lenses

Journal of the Optical Society of America A, 2017

Research paper thumbnail of Dispersion kernels for water wave simulation

ACM Transactions on Graphics, 2016

We propose a method to simulate the rich, scale-dependent dynamics of water waves. Our method pre... more We propose a method to simulate the rich, scale-dependent dynamics of water waves. Our method preserves the dispersion properties of real waves, yet it supports interactions with obstacles and is computationally efficient. Fundamentally, it computes wave accelerations by way of applying a dispersion kernel as a spatially variant filter, which we are able to compute efficiently using two core technical contributions. First, we design novel, accurate, and compact pyramid kernels which compensate for low-frequency truncation errors. Second, we design a shadowed convolution operation that efficiently accounts for obstacle interactions by modulating the application of the dispersion kernel. We demonstrate a wide range of behaviors, which include capillary waves, gravity waves, and interactions with static and dynamic obstacles, all from within a single simulation.

Research paper thumbnail of The relationship between dioptric power and magnification in progressive addition lenses

Ophthalmic and Physiological Optics, 2016

Research paper thumbnail of Full blind Bayesian denoising using scale mix-tures of Gaussians in the wavelet domain

Research paper thumbnail of Image Denoising using Scale Mixtures of

Research paper thumbnail of Title: "TEXTURE SYNTHESIS-BY-ANALYSIS BASED ON A MULTISCALE EARLYVISION MODEL

This paper introduces a new texture synthesis-by-analysis method, applying a visual-based approac... more This paper introduces a new texture synthesis-by-analysis method, applying a visual-based approach which has some important advantages over more traditional texture modeling and synthesis techniques. The basis of the method is to encode the textural information by sampling both the power spectrum and the histogram of homogeneously textured images. The spectrum is sampled in a log-polar grid by using a pyramid Gabor scheme. The input image is split into a set of 16 Gabor channels (using four spatial frequency levels and four orientations), plus a low-pass residual (LPR). The energy and equivalent bandwidths of each channel, as well as the LPR power spectrum and the histogram, are measured and the latter two are compressed. The synthesis process consists of generating 16 Gabor filtered independent noise signals with spectral centers equal to those of the Gabor filters, whose energy and equivalent bandwidths are calculated in order to reproduce the measured values. These band-pass sign...

Research paper thumbnail of Two-level adaptive denoising using Gaussian scale mixtures in overcomplete oriented pyramids

IEEE International Conference on Image Processing 2005, 2005