Publications and Presentations
2024
K. Hirakawa, D.A. LeMaster, J. Raffoul, D.B. Chenault, D.G. Crandall, L. Pezzaniti, “Experimental Comparison of 2x2 and 2x4 Patterned Microgrid Polarimetric Imaging Cameras,” SPIE Defense and Commercial Sensing, 2024.
J. Raffoul, D.A. LeMaster, K. Hirakawa, “Micro-Polarizer Array Demosaicking and Denoising,” SPIE Defense and Commercial Sensing, 2024.
Mitchell Grose, Jason Schmidt, Keigo Hirakawa, "Convolutional Neural Network for Improved Event-Based Shack-Hartmann Wavefront Reconstruction," Optica Applied Optics, 2024.
Osama AlSattam, Michael Mongin, Andrew Killian, Sidaard Gunasekaran, Keigo Hirakawa, "Toward Event-Based Noise-Robust High Density Particle Velocimetry," AIAA SciTech, 2024.
Kodai Kikuchi, Kohei Tomioka, Akira Honji, Takenobu Usui, Keigo Hirakawa, Kazuya Kitamura, “Hardware Implementation of Low-Latency Image Denoising with Wavelet Shrinkage and Noise2Noise-Based Learning for Ultra-High Definition Cameras,” IEEE International Conference on Consumer Electronics (ICCE), 2024. (Best Paper Award)
R. Wes Baldwin, Vijayan Asari, Keigo Hirakawa, "Sign-Coded Exposure Sensing for Noise-Robust High-Speed Imaging," IEEE Transaction on Computational Imaging, 2024.
Roseanna G. Lawandi, Zhanibek Bolatbek, Imad Agha, Keigo Hirakawa, Andrew Sarangan, "Continuously variable Fourier filters fabricated using varying-angle glancing angle deposition for chip-scale spectroscopy," Optica Applied Optics, 2024.
Sreelakshmi Sreeharan, Hui Wang, Keigo Hirakawa, Beiwen Li, "Aleatoric Uncertainty Quantification in Digital Fringe Projection Systems at a Per-Pixel Basis," Elsevier, Optics and Lasers in Engineering, 2024.
2023
Roseanna G. Lawandi, Zhanibek Bolatbek, Imad Agha, Keigo Hirakawa, Andrew Sarangan, "Single-Shot Spectroscopy Using Continuously Variable Filters," SPIE Nanoscience and Engineering, 2023.
Hsuan Lin, Keigo Hirakawa, "Data Driven Multiband Image Fusion That Preserves Wavelength-Specific Image Features," APSIPA Annual Summit and Conference, 2023.
Remona Heenkenda, Keigo Hirakawa, Andrew Sarangan, "A Tunable Transmission Filter Using Phase Change Materials (PCM) for Smart IR Night Vision Applications," SPIE Defense and Commercial Sensing, 2023.
Kodai Kikuchi, Kohei Tomioka, Takemichi Usui, Kazuya Kitamura, Keigo Hirakawa, "Low-Latency Shot Noise Reduction Method For Ultra-High Definition Cameras," IEICE Image Engineering, 2023. (IE Special Paper Award, Society Papers of the year)
Joseph Raffoul, Daniel LeMaster, Keigo Hirakawa, "Computationally Efficient and High Fidelity Log-Based Demosaicking for Degree of Linear Polarization," SPIE Future Sensing Technologies, 2022/2023.
Sarah Miller, Christina Karam, Achour Idoughi, Kodai Kikuchi, Keigo Hirakawa, "A Bayesian Perspective on Noise2Noise: Theory and Extensions," IEEE International Conference on Speech and Signal Processing, 2023.
Matthew Howard, Keigo Hirakawa, "Event-Based Visual Microphone," IEEE International Conference on Speech and Signal Processing, 2023. (Top 3% Paper)
2022
Joseph Raffoul, Daniel Lemaster, Keigo Hirakawa, "Framework for Improving DoLP and AoLP Reconstruction Quality in Microgrid Polarimeters," Optica Optics Express, vol 30, no. 26, p. 48004-48020, 2022.
Keigo Hirakawa, "Joint APS-DVS Sensor Optical Flow," IEEE International Conference on Multisensor Fusion and Integration, Workshop on Neuromorphic Event Sensor Fusion Algorithms and their Applications, 2022.
Luc Tinch, Nitesh Menon, Keigo Hirakawa, Scott McCloskey, "Event-Based Detection, Tracking, and Recognition of Unresolved Moving Objects," Advanced Maui Optical and Space Surveillance Technologies Conference, September 2022. (accepted)
Yeejin Lee, Keigo Hirakawa, "Loessless White Balance For Improved Lossless CFA Image and Video Compression,” IEEE Transactions on Image Processing, vol. 31, p. 3309-3321, 2022.
R. Wes Baldwin, Mohammed Almatrafi, Ruixu Liu, Vijayan Asari, Keigo Hirakawa, "A Time-Ordered Recent Event (TORE) Volumes for Event Cameras," IEEE Transactions on Pattern Analysis and Machine Intelligence.
2021
Remona Heenkenda, Keigo Hirakawa, Andrew Sarangan, “A Tunable Optical Filter using Phase Change Materials for Smart IR Night Vision Applications,” Optics Express, vol. 29, p. 33795-33803, 2021.
Remona Heenkenda, Andrew Sarangan, Keigo Hirakawa, "Switchable PCM Optical Filter for Automotive Color-IR Imaging," IEEE Photonics Conference, October 2021.
Keigo Hirakawa, Davide Migliore, "Introduction to Event Detection Cameras," IEEE International Conference on Computer Vision, Short Course, 2021.
Sarah Miller, Chen Zhang, Keigo Hirakawa, "Multi-Resolution Aitchison Geometry Image Denoising for Low-Light Photography," IEEE Transactions on Image Processing, vol. 30, p. 5724-5738, 2021.
Christina Karam, Kenjiro Sugimoto, Keigo Hirakawa, "Color-Compressive Bilateral Filter and Non-Local Means for High-Dimensional Images," SPIE Journal of Electronic Imaging, vol. 30, no. 2, March 2021.
Keigo Hirakawa, "Introduction to Event Detection Camera," IS&T Electronic Imaging Conference, Short Course, 2021.
2020
Charles Brookshire, Michael Uchic, Victoria Kramb, Tyler Lesthaeghe, Keigo Hirakawa, "L's Approach: Illumination Pattern Estimation Technique for Optical Microscopy," Wiley Journal of Microscopy, vol. 281, no. 3, p.243-254, October 2020.
Elhusain Saad, Keigo Hirakawa, "Improved Photometric Acceptance Testing In Image Feature Extraction Tasks," SPIE Journal of Electronic Imaging, vol. 29, no. 4, 2020, 043012.
Roseanna G. Lawandi, Keigo Hirakawa, Andrew M. Sarangan, "Spectroscopy using tunable liquid crystal Fourier filters," SPIE Nanoengineering: Fabrication, Properties, Optics, Thin Films, and Devices XVII, 2020.
Mohammed Almatrafi, R. Wes Baldwin, Kiyoharu Aizawa, and Keigo Hirakawa. "Distance Surface for Event-Based Optical Flow." IEEE Transactions on Pattern Analysis and Machine Intelligence 42, no. 7, p.1547-1556, 2020.
Mohammed Almatrafi, R. Wes Baldwin, Kiyoharu Aizawa, and Keigo Hirakawa. "Distance Surface for Event-Based Optical Flow." IEEE International Conference on Computational Photography (ICCP), 2020.
R. Wes Baldwin, Mohammed Almatrafi, Vijayan Asari, and Keigo Hirakawa. "Event Probability Mask (EPM) and Event Denoising Convolutional Neural Network (EDnCNN) for Neuromorphic Cameras." IEEE Computer Vision and Pattern Recognition (CVPR), 2020.
Charles Brookshire, Michael Uchic, Victoria Kramb, Tyler Lesthaeghe, and Keigo Hirakawa. "Estimation of the background illumination in optical reflectance microscopy." IS&T Electronic Imaging, Computational Imaging, 2020.
Yeejin Lee, and Keigo Hirakawa. "Shift-And-Decorrelate Lifting: CAMRA For Lossless Intra Frame CFA Video Compression." IEEE Signal processing Letters, 27, no. 1, p.461-465, 2020.
2019
Chen Zhang, Wu Cheng, and Keigo Hirakawa. "Corrupted Reference Image Quality Assessment of Denoised Images." IEEE Transactions on Image Processing 28.4 (2018): 1732-1747.
Christina Karam, Kenjiro Sugimoto, and Keigo Hirakawa. "Fast Convolutional Distance Transform." IEEE Signal Processing Letters 26.6 (2019): 853-857.
Jamie Stanton, Keigo Hirakawa, and Scott McCloskey. "Detecting Image Forgery Based On Color Phenomenology." Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition Workshops. 2019.
R. Wes Baldwin, Mohammed Almatrafi, Jason R. Kaufman, Vijayan Asari, and Keigo Hirakawa. "Inceptive Event Time-Surfaces for Object Classification Using Neuromorphic Cameras." International Conference on Image Analysis and Recognition. Springer, Cham, 2019. (Springer Best Paper Prize Award)
Rei Narita, Keigo Hirakawa, and Kiyoharu Aizawa. "Optical Flow Based Line Drawing Frame Interpolation Using Distance Transform to Support Inbetweenings." 2019 IEEE International Conference on Image Processing (ICIP). IEEE, 2019.
Mohammed Almatrafi, and Keigo Hirakawa. "DAViS Camera Optical Flow." IEEE Transactions on Computational Imaging, vol 6, p.369-407, 2020.
Matthew Howard, Andrew Sarangan, and Keigo Hirakawa. "Shortwave Infrared Fourier Multispectral Imaging." Imaging Systems and Applications. Optical Society of America, 2019.
Roseanna G. Lawandi, Keigo Hirakawa, Partha Banerjee, and Andrew M. Sarangan. "Fabrication of integrated single-chip Fourier spectrometers." Nanoengineering: Fabrication, Properties, Optics, Thin Films, and Devices XVI. Vol. 11089. International Society for Optics and Photonics, 2019.
Keigo Hirakawa. "Unifying principles of camera processing pipeline in the rapidly changing imaging landscape." IS&T Electronic Imaging, Camera Pipelines and Processing, 2019. (Keynote Presentation)
2018
Christina Karam, and Keigo Hirakawa. "Monte-Carlo acceleration of bilateral filter and non-local means." IEEE Transactions on Image Processing 27.3 (2017): 1462-1474.
Jiachao Zhang, Jie Jia, Andong Sheng, and Keigo Hirakawa. "Pixel Binning for High Dynamic Range Color Image Sensor Using Square Sampling Lattice." IEEE Transactions on Image Processing 27.5 (2018): 2229-2241.
Ruojun He, and Keigo Hirakawa. "Square Coded Aperture: A Large Aperture With Infinite Depth Of Field." IS&T Electronic Imaging, Computational Imaging, 2018.
Yeejin Lee, Keigo Hirakawa, and Truong Q. Nguyen. "Camera-aware multi-resolution analysis for raw image sensor data compression." IEEE Transactions on Image Processing 27, no. 6 (2018): 2806-2817.
Chuan Ni, Jie Jia, Matthew Howard, Keigo Hirakawa, and Andrew Sarangan. "Single-shot multispectral imager using spatially multiplexed Fourier spectral filters." JOSA B 35, no. 5 (2018): 1072-1079.
Jiachao Zhang, Andong Sheng, and Keigo Hirakawa. "A Wavelet-GSM Approach to Demosaicking." IEEE Signal Processing Letters 25, no. 6 (2018): 778-782.
Wu Cheng, and Keigo Hirakawa. "Towards optimal Denoising of image contrast." IEEE Transactions on Image Processing 27, no. 7 (2018): 3446-3458.
Christina Karam, Kenjiro Sugimoto, and Keigo Hirakawa. "Near-Constant Time Bilateral Filter for High Dimensional Images." In 2018 25th IEEE International Conference on Image Processing (ICIP), pp. 3244-3248. IEEE, 2018.
Rei Narita, Keigo Hirakawa, Kiyoharu Aizawa. "InBetweenings between Line Drawings of Consecutive Frames Using Distance Transformation for Animation Production Support." Forum on Information Technology, 2018. (Image Engineering Paper Award)
2017
Yeejin Lee, Keigo Hirakawa, and Truong Q. Nguyen. "Lossless compression of CFA sampled image using decorrelated Mallat wavelet packet decomposition." In 2017 IEEE International Conference on Image Processing (ICIP), pp. 2721-2725. IEEE, 2017.
Yeejin Lee, Keigo Hirakawa, and Truong Q. Nguyen. "Joint defogging and demosaicking." IEEE Transactions on Image Processing 26, no. 6 (2016): 3051-3063.
Jiachao Zhang, and Keigo Hirakawa. "Improved denoising via Poisson mixture modeling of image sensor noise." IEEE Transactions on Image Processing 26, no. 4 (2017): 1565-1578.
Keigo Hirakawa. "Challenges to designing forward-compatible camera processing pipeline." Picture Coding Symposium of Japan, 2017. (Keynote Presentation)
Keigo Hirakawa. "Fourier Multispectral Imaging: Measuring Spectra, One Sinusoid at a Time." In International Workshop on Computational Color Imaging, pp. 3-12. Springer, Cham, 2017. (Keynote Presentation)
2016
Jie Jia, Kenneth J. Barnard, and Keigo Hirakawa. "Fourier spectral filter array for optimal multispectral imaging." IEEE Transactions on Image Processing 25, no. 4 (2016): 1530-1543.
Elhusain Saad, and Keigo Hirakawa. "Defocus blur-invariant scale-space feature extractions." IEEE Transactions on Image Processing 25, no. 7 (2016): 3141-3156.
Jie Jia, Chuan Ni, Andrew Sarangan, and Keigo Hirakawa. "Guided filter demosaicking for Fourier spectral filter array." Electronic Imaging 2016, no. 2 (2016): 1-5.
Yi Zhang, and Keigo Hirakawa. "Combining inertial measurements with blind image deblurring using distance transform." IEEE Transactions on Computational Imaging 2, no. 3 (2016): 281-293.
Yi Zhang, and Keigo Hirakawa. "Blind deblurring and denoising of images corrupted by unidirectional object motion blur and sensor noise." IEEE Transactions on Image Processing 25, no. 9 (2016): 4129-4144.
2015
Jiachao Zhang, Keigo Hirakawa, and Xiaodan Jin. "Quantile analysis of image sensor noise distribution." In 2015 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), pp. 1598-1602. IEEE, 2015.
Wu Cheng, and Keigo Hirakawa. "Minimum risk wavelet shrinkage operator for poisson image denoising." IEEE Transactions on Image Processing 24, no. 5 (2015): 1660-1671.
Elhusain Saad, and Keigo Hirakawa. "Improving SURF interest point detection for defocus blur robustness." In 2015 IEEE International Conference on Image Processing (ICIP), pp. 3029-3033. IEEE, 2015.
Jia Jia, and Keigo Hirakawa. "Single-shot Fourier transform multispectroscopy." In 2015 IEEE International Conference on Image Processing (ICIP), pp. 4205-4209. IEEE, 2015.
Yi Zhang, and Keigo Hirakawa. "Fast spatially varying object motion blur estimation." In 2015 IEEE International Conference on Image Processing (ICIP), pp. 646-650. IEEE, 2015.
Christina Karam, Chong Chen, and Keigo Hirakawa. "Stochastic bilateral filter for high-dimensional images." In 2015 IEEE International Conference on Image Processing (ICIP), pp. 192-196. IEEE, 2015.
Wu Cheng, and Keigo Hirakawa. "Nonparametric empirical Bayes estimation for multiplicative multiscale innovation in photon-limited imaging." In 2015 IEEE International Conference on Image Processing (ICIP), pp. 1855-1859. IEEE, 2015.
Jie Jia, Chuan Ni, Andrew Sarangan, and Keigo Hirakawa. "Fourier multispectral imaging." Optics express 23, no. 17 (2015): 22649-22657.
Chuan Ni, Jie Jia, Keigo Hirakawa, and Andrew Sarangan. "Design and fabrication of sinusoidal spectral filters for multispectral imaging." In Nanoengineering: Fabrication, Properties, Optics, and Devices XII, vol. 9556, p. 95560I. International Society for Optics and Photonics, 2015.
2014
Xiaodan Jin, Zhenyu Xu, and Keigo Hirakawa. "Noise parameter estimation for Poisson corrupted images using variance stabilization transforms." IEEE Transactions on Image Processing 23, no. 3 (2014): 1329-1339.
Daniel A. LeMaster, and Keigo Hirakawa. "Improved microgrid arrangement for integrated imaging polarimeters." Optics letters 39, no. 7 (2014): 1811-1814.
Jan Tore Korneliussen, and Keigo Hirakawa. "Camera processing with chromatic aberration." IEEE Transactions on Image Processing 23, no. 10 (2014): 4539-4552.
Chen Zhang, and Keigo Hirakawa. "Blind full reference quality assessment of Poisson image denoising." In 2014 IEEE International Conference on Image Processing (ICIP), pp. 2719-2723. IEEE, 2014.
Keigo Hirakawa, and Kenneth J. Barnard. "Fourier spectral filter array design for multispectral image recovery." In Imaging Systems and Applications, pp. IM1C-5. Optical Society of America, 2014.
Keigo Hirakawa, and Daniel A. LeMaster. "Fourier domain design of microgrid imaging polarimeters with improved spatial resolution." In Polarization: Measurement, Analysis, and Remote Sensing XI, vol. 9099, p. 909906. International Society for Optics and Photonics, 2014.
2013
Yi Zhang, and Keigo Hirakawa. "Blur processing using double discrete wavelet transform." In Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, pp. 1091-1098. 2013.
Pižurica, Aleksandra, Javier Portilla, Keigo Hirakawa, and Karen Egiazarian. "Advanced statistical tools for enhanced quality digital imaging with realistic capture models." (2013): 140.
Xiaodan Jin, and Keigo Hirakawa. "Approximations to camera sensor noise." In Image Processing: Algorithms and Systems XI, vol. 8655, p. 86550H. International Society for Optics and Photonics, 2013.
Kongfeng Zhu, Keigo Hirakawa, Vijayan Asari, and Dietmar Saupe. "A no-reference video quality assessment based on laplacian pyramids." In 2013 IEEE International Conference on Image Processing, pp. 49-53. IEEE, 2013.
Keigo Hirakawa. "Analysis of Motion Blur Using Double Discrete Wavelet Transform," NOBIM Norway National Conference on Image Processing and Pattern Recognition, 2013. (Keynote Presentation)
2012
Ayan Chakrabarti, Keigo Hirakawa, and Todd Zickler. "Color constancy with spatio-spectral statistics." IEEE Transactions on Pattern Analysis and Machine Intelligence 34, no. 8 (2011): 1509-1519.
Wu Cheng, and Keigo Hirakawa. "Corrupted reference image quality assessment." In 2012 19th IEEE International Conference on Image Processing, pp. 1485-1488. IEEE, 2012.
Xiaodan Jin, and Keigo Hirakawa. "Analysis and processing of pixel binning for color image sensor." EURASIP Journal on Advances in Signal Processing 2012, no. 1 (2012): 125.
2011
Keigo Hirakawa, and Patrick J. Wolfe. "Rewiring Filterbanks for Local Fourier Analysis: Theory and Practice." IEEE Transactions on Information Theory 57, no. 8 (2011): 5360-5374.
Vikas Ramachandra, Keigo Hirakawa, Matthias Zwicker, and Truong Nguyen. "Spatioangular prefiltering for multiview 3D displays." IEEE Transactions on Visualization and Computer Graphics 17, no. 5 (2010): 642-654.
Keigo Hirakawa, and Paul M. Simon. "Single-shot high dynamic range imaging with conventional camera hardware." In 2011 International Conference on Computer Vision, pp. 1339-1346. IEEE, 2011.
Keigo Hirakawa, and Jing Gu. "High resolution subpixel and subframe rendering for color flatpanel and projector displays." In 2011 18th IEEE International Conference on Image Processing, pp. 1725-1728. IEEE, 2011.
Keigo Hirakawa, "Spectral Filter Array Design for Multispectral Image Recovery," IAPR Computational Color Imaging Workshop, 2011. (Keynote Presentation)
2010
Keigo Hirakawa, and Patrick J. Wolfe. "Optimal exposure control for high dynamic range imaging." In 2010 IEEE International Conference on Image Processing, pp. 3137-3140. IEEE, 2010.
Jing Gu, Patrick J. Wolfe, and Keigo Hirakawa. "Filterbank-based universal demosaicking." In 2010 IEEE International Conference on Image Processing, pp. 1981-1984. IEEE, 2010.
Keigo Hirakawa. "Iterative exposure bracketing." In Digital Image Processing and Analysis, p. DMC4. Optical Society of America, 2010.
Vikas Ramachandra, Keigo Hirakawa, Matthias Zwicker, and Truong Q. Nguyen. "Spatio-angular sharpening for multiview 3D displays." In 2010 IEEE International Conference on Acoustics, Speech and Signal Processing, pp. 750-753. IEEE, 2010.
2009
Hirakawa, Keigo, and Patrick J. Wolfe. "Skellam shrinkage: Wavelet-based intensity estimation for inhomogeneous poisson data." IEEE Transactions on Information Theory 58, no. 2 (2011): 1080-1093.
Keigo Hirakawa, and Patrick J. Wolfe. "Efficient multivariate Skellam Shrinkage for denoising photon-limited image data: An empirical Bayes approach." In 2009 16th IEEE International Conference on Image Processing (ICIP), pp. 2961-2964. IEEE, 2009.
Keigo Hirakawa, and Patrick J. Wolfe. "SkellamShrink: Poisson intensity estimation for vector-valued data." In 2009 IEEE International Conference on Acoustics, Speech and Signal Processing, pp. 3441-3444. IEEE, 2009.
Keigo Hirakawa, Farhan Baqai, and Patrick J. Wolfe. "Wavelet-based Poisson rate estimation using the Skellam distribution." In Computational Imaging VII, vol. 7246, p. 72460R. International Society for Optics and Photonics, 2009.
Keigo Hirakawa. "Advanced Digital Camera Processing: Modern Architecture and Future Challenges," Picture Coding Symposium of Japan-Image Media Processing Symposium, 2009. (Keynote Presentation)
Keigo Hirakawa. "Optimization for Spatio-Color Fidelity." Computer Software Association of Japan-SigFVI, 2009. (Keynote Presentation)
2008
Keigo Hirakawa, and Patrick J. Wolfe. "Spatio-spectral color filter array design for optimal image recovery." IEEE Transactions on Image Processing 17, no. 10 (2008): 1876-1890.
Keigo Hirakawa. "Color filter array image analysis for joint denoising and demosaicking." Single-Sensor Imaging: Methods and Applications for Digital Cameras, Rastislav Lukac (Ed.), CRC Press, pp. 239–261, 2008.
Keigo Hirakawa, and Patrick J. Wolfe. "Spatio-spectral sampling and color filter array design." Single-Sensor Imaging: Methods and Applications for Digital Cameras, Rastislav Lukac (Ed.), CRC Press, pp. 239–261, 2008.
Keigo Hirakawa. "Cross-talk explained." In 2008 15th IEEE International Conference on Image Processing, pp. 677-680. IEEE, 2008.
Ayan Chakrabarti, Keigo Hirakawa, and Todd Zickler. "Color constancy beyond bags of pixels." In 2008 IEEE Conference on Computer Vision and Pattern Recognition, pp. 1-6. IEEE, 2008.
Keigo Hirakawa, and Patrick J. Wolfe. "Advancing the digital camera pipeline for mobile multimedia: Key challenges from a signal processing perspective." In 2008 IEEE International Conference on Acoustics, Speech and Signal Processing, pp. 5332-5335. IEEE, 2008.
Ayan Chakrabarti, and Keigo Hirakawa. "Effective separation of sparse and non-sparse image features for denoising." In 2008 IEEE International Conference on Acoustics, Speech and Signal Processing, pp. 857-860. IEEE, 2008.
Keigo Hirakawa. "Fourier and filterbank analyses of signal-dependent noise." In 2008 IEEE International Conference on Acoustics, Speech and Signal Processing, pp. 3517-3520. IEEE, 2008.
Keigo Hirakawa, and Patrick J. Wolfe. "Second-generation color filter array and demosaicking designs." In Visual Communications and Image Processing 2008, vol. 6822, p. 68221P. International Society for Optics and Photonics, 2008.
Keigo Hirakawa. "Spatio-Spectral Sampling in Multispectral Imaging," IS&T Color in Graphics, Image, and Vision, 2008. (Keynote Presentation)
2007
Keigo Hirakawa, and Patrick J. Wolfe. "Spatio-spectral color filter array design for enhanced image fidelity." In 2007 IEEE International Conference on Image Processing, vol. 2, pp. II-81. IEEE, 2007. (Most Innovative Paper Award)
Keigo Hirakawa, and Patrick J. Wolfe. "Fourier domain display color filter array design." In 2007 IEEE International Conference on Image Processing, vol. 3, pp. III-429. IEEE, 2007.
Keigo Hirakawa. "Signal-dependent noise characterization in Haar filterbank representation." In Wavelets XII, vol. 6701, p. 67011I. International Society for Optics and Photonics, 2007.
Keigo Hirakawa, Xiao-Li Meng, and Patrick J. Wolfe. "A framework for wavelet-based analysis and processing of color filter array images with applications to denoising and demosaicing." In 2007 IEEE International Conference on Acoustics, Speech and Signal Processing-ICASSP'07, vol. 1, pp. I-597. IEEE, 2007.
2006
Keigo Hirakawa, and Thomas W. Parks. "Image denoising using total least squares." IEEE Transactions on image processing 15, no. 9 (2006): 2730-2742.
Keigo Hirakawa, and Thomas W. Parks. "Joint demosaicing and denoising." IEEE Transactions on Image Processing 15, no. 8 (2006): 2146-2157.
Keigo Hirakawa, and Xiao-Li Meng. "An empirical Bayes EM-wavelet unification for simultaneous denoising, interpolation, and/or demosaicing." In 2006 International Conference on Image Processing, pp. 1453-1456. IEEE, 2006.
2005
Keigo Hirakawa, and Thomas W. Parks. "Adaptive homogeneity-directed demosaicing algorithm." IEEE Transactions on Image Processing 14, no. 3 (2005): 360-369.
Keigo Hirakawa, and Thomas W. Parks. "Image denoising for signal-dependent noise." In Proceedings.(ICASSP'05). IEEE International Conference on Acoustics, Speech, and Signal Processing, 2005., vol. 2, pp. ii-29. IEEE, 2005.
Keigo Hirakawa, and Thomas W. Parks. "Joint demosaicing and denoising." In 2006 International Conference on Image Processing, pp. III-309. IEEE, 2005.
Hirakawa, Keigo, and Thomas W. Parks. "Chromatic adaptation and white-balance problem." In IEEE International Conference on Image Processing 2005, vol. 3, pp. III-984. IEEE, 2005.
2003
Hirakawa, Keigo, and Thomas W. Parks. "Adaptive homogeneity-directed demosaicing algorithm." In IEEE International Conference on Image Processing 2003, vol. 3, pp. III-669. IEEE, 2003.
Keigo Hirakawa, and Thomas W. Parks. "Tone-Curve Filtering," In IEEE Western New York Image Processing Workshop, 2003. (Best Paper Award)