Image Processing Algorithms

Revision as of 13:14, 10 May 2013

Image Dithering

Optimized Error Diffusion for Image Display, B.W. Kolpatzik, C.A. Bouman - The design is based on the lowpass characteristic of the contrast sensitivity of the human visual system. The Filter is chosen so that a cascade of the quantization system and the observer's visual modulation transfer function yields a whitened error spectrum. The resulting images contain mostly high frequency components of the display error, which are less noticeable to the viewer.
Discussion

Image Formats

v210 v210 is a Quicktime format for storing 10bit YUV video. It's supported by qtinput and deepcolor tools.

Image Denoising

An efficient algorithm for NL Means
An Improved Non-Local Denoising Algorithm, Bart Goossens, Hiêp Luong, Aleksandra Pižurica and Wilfried Philips - In this paper, we show that the NLMeans algorithm is basically the first iteration of the Jacobi optimization algorithm for robustly estimating the noise-free image. Based on this insight, we present ad- ditional improvements to the NLMeans algorithm and also an extension to noise reduction of coloured (corre- lated) noise.
discussion

-Salt and Pepper Noise

http://www.icgst.com/gvip/Volume6/Issue3/P1150636003.pdf
Discussion and samples (amazing!)

Image Inpainting

Object Removal by Exemplar-Based Inpainting. A. Criminisi, P. Perez, K. Toyama
Source code from Qiushuang Zhang
ExInPaint by Fizick - An avisynth plugin based on the above papers
Discussion of ExInPaint
Fast Image Inpainting Based on Coherence Transport - Homepage Homepage
Fast Image Inpainting Based on Coherence Transport - High quality version of paper, pdf. Based on a detailed analysis of stationary first order transport equations the current paper develops a fast noniterative method for image inpainting. It traverses the inpainting domain by the fast marching method just once while transporting, along the way, image values in a coherence direction robustly estimated by means of the structure tensor. Depending on a measure of coherence strength the method switches continuously between diffusion and directional transport. It satisfies a comparison principle.
Discussion of AVSInPaint - AVSInPaint is based on the above papers.
Digital inpainting: a tutorial - This tutorial will cover the most recent contributions in image inpainting / image completion, video inpainting, and 3-D surface completion. (from 2007)

Image Scaling

Subpixel Image Scaling for Color Matrix Displays, Michiel A. Klompenhouwer, Gerard de Haan - Subpixel rendering’ algorithms are being used to convert an input image to subpixel-corrected dis- play images. This paper deals with the consequences of the subpixel structure, and the theoretical background of the resolution gain. We will show that this theory allows a low-cost implementation in an image scaler. This leads to high flexibility, allowing different subpixel arrangements and a simple control over the trade-off between perceived resolution and color errors.
Discussion

-Spine Scaling

http://lear.inrialpes.fr/people/triggs/pubs/Triggs-iccv01-subpix.pdf
http://www.fugroairborne.com/resources/technical_notes/time_domain_em/pdfs/Akima_tension_III.pdf
http://www.korf.co.uk/spline.pdf
http://math.lanl.gov/~mac/papers/numerics/H83.pdf
http://www.cs.cmu.edu/~fp/courses/graphics/asst5/catmullRom.pdf
Further discussion on spline resizing and links
another discussion

Image Deblurring

A scaled gradient projection method for constrained image deblurring - A class of scaled gradient projection methods for optimization problems with simple constraints is considered. These iterative algorithms can be useful in variational approaches to image deblurring that lead to minimized convex nonlinear functions subject to non-negativity constraints and, in some cases, to an additional flux conservation constraint. A special gradient projection method is introduced that exploits effective scaling strategies and steplength updating rules, appropriately designed for improving the convergence rate. We give convergence results for this scheme and we evaluate its effectiveness by means of an extensive computational study on the minimization problems arising from the maximum likelihood approach to image deblurring. Comparisons with the standard expectation maximization algorithm and with other iterative regularization schemes are also reported to show the computational gain provided by the proposed method.
A Scaled Gradient Projection Method for Constrained Image Deblurring SBonettini, R Zanella and L Zanni - A class of scaled gradient projection methods for optimization problems with simple constraints is considered. These iterative algorithms can be useful in variational approaches to image deblurring that lead to minimize convex nonlinear functions subject to nonnegativity constraints and, in some cases, to an additional °ux conservation constraint. A special gradient projection method is introduced that exploits e®ective scaling strategies and steplength updating rules, appropriately designed for improving the convergence rate. We give convergence results for this scheme and we evaluate its e®ectiveness by means of an extensive computational study on the minimization problems arising from the maximum likelihood approach to image deblurring. Comparisons with the standard expectation maximization algorithm and with other iterative regularization schemes are also reported to show the computational gain provided by the proposed method.
Discussion - Seems to need camera parameters, so may be a dead end.

Standardized Video Test Patterns

Rec. ITU-R BT.801-1, Annex 2, P13-15
Rec. ITU-R BT.1729, Page16
The colorbars values are listed below:

Rec. ITU-R BT.801-1
Description of encoded colour-bar signals according to the 4:2:2 level
of Recommendation ITU-R BT.601
100/0/75/0 colour bars
color		Y	Cb	Cr
white		235	128	128
yellow		162	 44	142
cyan		131	156	 44
green		112	 72	 58
magenta		 84	184	198
red		 65	100	212
blue		 35	212	114
black		 16	128	128

Description of encoded colour-bar signals according to the 4:2:2 level
of Recommendation ITU-R BT.601
100/0/100/0 colour bars
AND
Rec. ITU-R BT.1729
Appendix 2
100% colorbars
color		Y	Cb	Cr
white		235	128	128
yellow		210	 16	146
cyan		170	166	 16
green		145	 54	 34
magenta		106	202	222
red		 81	 90	240
blue		 41	240	110
black		 16	128	128

Discussion of standards references

SuperResolution

http://auricle.dyndns.org/ALE/
http://www.soe.ucsc.edu/~milanfar/software/superresolution.html
http://www.ece.lsu.edu/ipl/Demos.html
http://ericpbennett.com/VideoEnhancement/BennettMcMillanSIGGRAPH.pdf
http://www.imse.cnm.es/Xfuzzy/xfpapers.html
http://www.imse.cnm.es/online/2005/ANNIE2005.JGR.pdf
http://www.escet.urjc.es/~asanz/investigacion_en.html
http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2009/381673
http://www.faculty.idc.ac.il/toky/Publications/Journal/superRes.pdf
http://www.utia.cas.cz/files/Soutez_08/Aplikace/Sroubek/gui_help_v12.pdf
further links and discussion on SuperResolution

Image Registration

http://www.nashruddin.com/phase-correlation-function-in-opencv.html#results
http://www.wedesoft.demon.co.uk/hornetseye-api/files/phasecorrelation-txt.html
https://scien.stanford.edu/pages/labsite/2000/ee392j/projects/liang_report.pdf

Deinterlacing

http://image.diku.dk/sunebio/KellerLauzeNielsen.pdf
http://www.eurasip.org/Proceedings/Eusipco/Eusipco2005/defevent/papers/cr1859.pdf
http://prestospace.org/training/images/iccvg2004.pdf
Short discussion on deinterlacing

Image Rotation

These are based on the fast 3 shear method

First shear : x' = x - tan (theta/2) * y
Second shear : y' = y + sin(theta) * x
Third shear : x' = x - tan (theta/2) * y

http://treskunov.net/anton/Software/doc/fast_and_high_quality_true_color_bitmap_rotation_function.html
http://web.archive.org/web/20040627185405/http://splorg.org/people/tobin/projects/israel/projects/paeth/rotation_by_shearing.html
http://bigwww.epfl.ch/publications/unser9502.pdf
http://www.leptonica.com/rotation.html
Further discussion and links

Seam Carving

http://www.faculty.idc.ac.il/arik/
ftp://ftp1.idc.ac.il/Arik_shamir/SCweb/vidret/index.html
ftp://ftp1.idc.ac.il/Arik_shamir/SCweb/vidret/vidret.pdf
Short Discussion - Avisynth has a ReTarget plugin for this.

todo: move to different section and category