Digital Imaging Technologies

We've actually been doing digital imaging for quite a long time. We played significant roles within the University of Kentucky's Center for Visualization and Virtual Environments, but digital imaging actually started to be a significant research topic for us in 1994, when we built the world's first Linux PC cluster supercomputer. In order to show that those "PCs on shelves" actually were coordinated as a single system, we implemented video walls on our clusters. By 1996, we had a 6400x4800 pixel video wall using a 4x4 array of Sony monitors driven by a 32-node cluster... but where do you find 30MP images in 1996? So, we began developing technologies to improve digital cameras and electronic imaging technologies: primarily doing what's now called computational photography. It's only over the last decade or so that we've been publishing this work outside of the parallel supercomputing community.

Just as our parallel computing research tends to emphasize leveraging commodity technologies, so to does our digital imaging work. For example, the image above was captured using a peephole as a fisheye lens for a digital camera. Much of our work has involved reprogramming Canon PowerShot cameras using CHDK, and we've also built custom cameras using standard components such as the ESP32-CAM. In general, we like our research results to not only have a theoretical contribution, but also some immediately practical applications.

Formal Research Presentations and Publications

EI2024: Leveraging Pixel Value Certainty in Pixel-Shift and Other Multi-Shot Super-Resolution Processing (preprint, parsek software homepage)

EI2023: Making Digital Cameras Less Attractive Targets for Theft (preprint, poster, DOI as published)

EI2023: Digital Camera Obscuras (preprint, slides, DOI as published)

EI2022: An improved raw image enhancement algorithm using a statistical model for pixel value error (slides, DOI as published)

EI2022: ESP32-CAM as a programmable camera research platform (slides, DOI as published)

EI2022: Capture optimization for composite images (poster, DOI as published)

EI2021: Mask recognition in the covered safe entry scanner

EI2021: An ultra-low-cost large-format wireless IoT camera

EI2021: Programmable liquid crystal apertures and filters for photographic lenses

EI2020: Camera unavoidable scene watermarks: A method for forcibly conveying information onto photographs

EI2020: Characterization of camera shake (WWW site)

EI2020: Camera support for use of unchipped manual lenses (WWW site)

EI2020: Non-uniform integration of TDCI captures (WWW site)

EI2020: Senscape: Modeling and presentation of uncertainty in fused sensor data live image streams (WWW site)

EI2019: Autocorrelation-based, passive, non-contact, photoplethysmography: Computationally-efficient, noise-tolerant, extraction of heart rates from video (slides)

EI2019: Credible repair of Sony main-sensor PDAF striping artifacts (slides)

EI2019: Shuttering methods and the artifacts they produce (poster)

EI2019: Self-contained, passive, non-contact, photoplethysmography: Real-time extraction of heart rates from live view within a Canon Powershot (slides)

EI2018: Lessons from design, construction, and use of various multicameras (slides)

EI2018: Multispectral, high dynamic range, time domain continuous imaging

EI2017: A Canon Hack Development Kit implementation of Time Domain Continuous Imaging

EI2017: Refining raw pixel values using a value error model to drive texture synthesis (slides)

EI2017: TIK: a time domain continuous imaging testbed using conventional still images and video (slides)

EI2017: Temporal super-resolution for time domain continuous imaging (slides)

EI2016: Use of flawed and ideal image pairs to drive filter creation by genetic programming

EI2016: Scene appearance change as framerate approaches infinity (slides)

EI2016: Mixing and matching sensor format with lens coverage (slides)

EI2016: Sony ARW2 compression: Artifacts and credible repair (slides)

EI2015: ISO-less? (slides, preprint)

EI2015: Frameless representation and manipulation of image data (preprint)

EI2014: Out-of-focus point spread functions (slides, preprint)

EI2014: Frameless, time domain continuous image capture (slides, preprint)

EI2013: FUJIFILM X10 white orbs and DeOrbIt (slides, preprint)

EI2012: Reprocessing Anaglyph Images (slides, preprint)

Informal External Publications

In most informal places, Prof. Dietz posts as profhankd

CHDK Lua Reference Card: a tri-fold reference card Prof. Dietz made for the Canon Hack Development Kit (CHDK) Lua programming environment
A Poorly Focused Talk: a talk about what defocus really does, presented by Prof. Dietz January 16, 2014 for the Creative Camera Club, Inc. of Lexington, KY
Prof. Dietz home page at Instructables: digital camera obscuras, safely shooting the Sun, DupliHood, single-shot anaglyph capture, large-format camera lensboards and digital backs, etc.
Prof. Dietz home pages at Printables and Thingiverse: over 100 3D-printable designs, most involving custom camera parts such as Arca Swiss mounts, camera obscuras, LOTS of lens adapters, fisheye and bird's eye cameras, stereo cameras, parametric lens caps/filters, etc.; Thingiverse has become unreliable losing indexes to posted things, thus, from 2022, designs are also posted at Printables
Prof. Dietz home page at DPReview (and the Technology Enabling Art challenge series): over 10K posts, mostly in the Adapted Lens and DIY forums; also host of the Technology Enabling Art challenge series
PentaxForums, Dyxum, FDReview, and AllPhotoLenses: web sites that archive reviews of old lenses; Prof. Dietz has reviewed most of his lenses (now over 250)

Research Products & Spin-Offs

Selecting IBIS Zoom Focal Length: a simple WWW utility that predicts IBIS effectiveness with various focal length settings so you can obtain optimal performance with a single focal length over a given zoom lens range
KentuckY Raw Error Modeler: KREMY: pronounced "creamy," this free software dramatically reduces noise in raw images by use of pixel value error modeling -- without smoothing and without AI methods
LArge FOrmat DIgital Scanner: Lafodis160: a 2.6GP large-format camera using an ESP32-CAM sensor, with build cost well under $100
Covered Safe Entry Scanner: hardware/software to recognize when individuals are properly masked duringv these pandemic times
Senscape Painting Algorithms: this includes the KVIRP (Kentucky's Visual / Infra Red Painter) and Wakam (WAlabot Kentucky cAMera) cameras and painting algorithms that integrate visible, thermal, and radar image data
KentuckY ARW Stripe Removal: KARWY-SR: is free software to credibly repair the (rare) stripe artifacts that occur due to PDAF pixel shading/reflections
KentuckY ARW wrapper: KARWY: is free software to credibly repair compression artifacts in Sony compressed raw (ARW) files
Temporal Imaging Kentucky: TIK: software synthesizing time domain continuous image data from conventional video and still images; allows virtual exposures to be made after capture varying when the shutter is triggered and what the effective shutter speed is
FourSee TDCI Camera Prototype: photos and overview of the FourSee multi-camera, which is capable of capturing high-framerate, high-dynamic-range, video synthesized from coordinated captures using four PowerShot N
FourSee TDCI Camera Prototype: photos and overview of the FourSee multi-camera, which is capable of capturing high-framerate, high-dynamic-range, video synthesized from coordinated captures using four PowerShot N
ISO-less? slides: Slides explaining ISO-less phenomena and how to use them to improve exposure
Large Format Digital: a white paper explaining why large format digital sensors make sense
Custom Lensboards For A Large-Format Camera: an instructable about making lensboards for 4x5 and other large-format cameras
Zero-Cost Built-In Bounce Flash: an instructable about using your finger to nudge a pop-up flash toward the ceiling... which works very nicely with the Sony NEX-7
Large Format Adapter For Your Mirrorless Camera: an instructable about using your mirrorless camera as a digital back for a large-format film camera
DeOrbIt synthesizes replacements for Fuji-like white orbs: The Fujifilm X10 has become infamous for the "white orbs" it sometimes produces; this tool replaces the blobs with more natural-looking synthesized structures
Using Kiev-10/Kiev-15 Lenses On Digital Cameras: an instructable about the use of Kiev 10/15 lenses on modern digital cameras
Paper preprint (PDF) and slides (PDF) for Reprocessing Anaglyph Images: Presented January 26, 2012 by Prof. Dietz at the IS&T/SPIE Electronic Imaging conference; paper to appear in the proceedings
My lenses: An annotated listing of (most) lenses I'm working with in my research; there are over 100, mostly old lenses purchased via eBay
Slides on PSF and Bokeh (PDF) and Apertures and Viewpoints (PDF): slides for two lectures Prof. Dietz gave in CS585 Computational Photography at the University of Kentucky, Sept. 28 and Sept 30, 2011
C-Mount Lenses for mirrorless micro 4/3 and APS-C?: an instructable about the use of C-mount lenses on cameras with sufficiently short flange distances, but larger sensors than the lenses were designed to cover... mostly reporting a negative result
Custom New Look for an Old Lens: an instructable about customizing/repairing the non-optical parts of old lenses
Use Your Camera To Capture "3D" Anaglyphs: an instructable about direct capture of anaglyphs using a reversible sub-$1 mod to a camera; although it does not require any special processing of the images, this is a spin-off of our computational photography work involving analysis and processing of out-of-focus image content
Cleaning Camera Equipment: a short overview of Dietz's take on cleaning cameras and lenses
Using Ultra-Fast Lenses on DSLR Cameras: an instructable about equipment lenses with f/numbers well below 2.0, e.g., Kowa 1:1 55mm
M42 Lens Aperture Control on Modern DSLRs: a little instructable about M42 preset, auto/man, and auto apertures
Technology Enabling Art: a dpreview challenge series attempting to encourage use of new digital imaging technologies
Old Film Camera Lenses On New Digital Cameras: discusses use of old film SLR lenses on new DSLRs
Big Old Camera, Tiny New Sensor: discusses use of an old 4x5 sheet film camera as a webcam
Capture Control Of Digital Cameras: a "work in progress" overview/survey of tethered image capture issues and techniques
Fisheye digital imaging for under $20: using a cheap digital camera with a door viewer peephole
RGB-NIR extraction from a single RAW image: a very simple linear technique using unmodified digital cameras
Accessories for exposure calibration: a really cool thing you can do with your lenscap to capture colors more accurately; this concept also is described in an instructable: Improve Color Accuracy In Your Photos
Color LCD Panel Subpixel Rendering (local copy): about use of subpixel techniques for general image rendering, as implemented in VWLib; this page was last modified December 15, 1998
VWLib: Video Wall Library: a virtual frame buffer for cluster supercomputers and various tools using it; our group built the world's first Linux PC cluster video wall back in 1994, and VWLib was the portable library we later released for others to use

External Links (not ours)

Cambridge in Colour: This is "a learning community for photographers" with some excellent tutorials including a variety of interactive displays and calculators
English homepage of Camera & Imaging Products Association (CIPA): CIPA Guidelines standardize how camera specifications are listed, etc.
http://www.dpreview.com/: A fairly technical site discussing digital photography equipment
http://www.imaging-resource.com/: A fairly technical site discussing digital photography equipment
http://www.pentaxforums.com/: A fairly technical Pentax-oriented site
http://www.dyxum.com/: A fairly technical Konica/Minolta/Sony-oriented site
http://www.mflenses.com/: A site dedicated to manual focus lens sample images, data, and reviews
http://www.camerapedia.org/: A free-content encyclopedia of camera info; for example, here is the longest list of M42 lenses I've seen thus far

At the University of Kentucky

Introduction to digital photography: a brief overview originally prepared for a free short course offered during Engineer's Day open house at the University of Kentucky's Department of Electrical & Computer Engineering; latest update is 20210517
Homepage for the University of Kentucky's Digital Photography Club: not active since 2011, but it could be?

The only thing set in stone is our name.