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Digital restoration opens up the exciting possibility of allowing old
media to be appreciated as though it were new media recreating the
original viewing and listening experience when the originals were
created. Restoration can even go beyond this and remove defects
introduced by the original recording or playback equipment.
31 White Papers
A method for evaluation of parasitic frequency modulation (wow) in archival audio is presented. The proposed approach utilizes sinusoidal components as their variations are highly correlated with the distortion variations. The sinusoidal components are extracted from audio signal by means of sinusoidal modeling procedures being often severely distorted and in case of wow also signficantly modulated.../...
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In this paper an algorithmic approach to the wow defect characteristic evaluation is presented. The approach is based
on a sinusoidal analysis comprising both amplitude and phase spectra processing. The frequency trajectories
depicting the distortion are built on a basis of amplitude, frequency and phase dependencies and are further used for
wow characteristic evaluation. Additionally the experiments concerning the neural-network-based prediction applied
to the characteristic are performed. The obtained results are compared to linear-prediction.../...
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This document contains a proposal for description of the condition of audiovisual essence, i.e. its technical quality and the defects it may have. Proposed descriptors are conformant to the MPEG-7 standard.
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This paper proposes a method based on the Dempster-Shafer evidence theory for the detection blotches in digitized archive film sequences.
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Blotch Detection for Digital Archives Restoration based on the Fusion of Spatial and Temporal Detectors,
This paper proposes a method based on the Dempster-Shafer evidence theory for the detection of blotches in digitized archive film sequences. The detection scheme relies on the fusion of two uncorrelated fast, no motion compensated, spatio-temporal blotch detectors. The imprecision and uncertainty of botch detectors are modeled using Dempster-Shafer evidence theory, which improves the decision, by taking into acoount the ignorance and the conflict between detectors. We found that this combination scheme improves the global performance, and compares favorably to the motion compensated, complex and time consuming blotch detection methods, for reat archive film sequences.
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The aim of this work is to present algorithm for the analog optical sound track translation to the digital sound. It can be use to make restoration of the old film soundtracks. Instead of repair sound, digital pictures of the sound track can be corrected, and then translated it to restored digital
sound. This method can also be useful in cases when the film tape is damaged and it can't be play in traditional way because it will split. In this document was featured method of the optical sound track digitalization, algorithm for the picture to sound translation and and results of it work.
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Algorithms for determining the wow distortion characteristic are proposed. These are the power-line-hum tracking algorithm, the high-frequency-bias tracking algorithm, and the algorithm based on an adaptive analysis of the center of gravity of the spectrum of the distorted signal. All of the algorithms presented allow a hardware- or software-based implementation.
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Detection and Tracking Scheme for Line Scratch Removal in an Image Sequence
A detection and tracking approach is proposed for line scratch removal in a digital film restoration process. Unlike random impulsive distortions such as dirt spots, line scratch artifacts persist across several frames. Hence, motion compensated methods will fail, as well as single-frame methods if scratches are unsteady or fragmented .../...
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We propose an adaptive spatio-temporal approach for the detection of dirt in archive film sequences. By combining
useful features from conventional stand-alone spatial and temporal approaches our method achieves better performance
in terms of both correct dirt detection rate and false alarm rate.../...
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We propose a novel approach for the detection of temporally impulsive dirt impairments in archived film sequences. Our
method does not require motion compensation and uses raw differences between the current frame and each of the
previous and next frames to extract a confidence signal which is used to localize and label dirt regions.../...
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Author of this paper participated in the development of several algorithms for wow and flutter characteristic determination. The algorithms were found useful in some real-life restoration procedures, however, there was no study of their capabilities in terms of the maximal determined modulation frequency. This paper presents such a study for three algorithms, i.e. the power-line hum tracker, high frequency bias tracker, and the centre of gravity tracker. In the paper a short description of the algorithms is followed by a theoretical study of the maximal modulation frequency determined by the algorithms. Next, the experimental part is given with simulations which confirm the findings from the theoretical part. The paper ends with conclusions.
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This paper presents a method for wow defect evaluation. The method is based on tonal components detection in STFT frames. Extracted harmonic elements are joined together to form tracks. The pitch variation curve pvc is created from the selected tracks. Pvc course is considered to depict the wow defect, therefore it can be used for parasite modulation removal.
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In this paper, we propose a novel approach to patch matching in exemplar-based inpainting. Our field of
concern is movie restoration, particularly scratch concealment. Here we want to focus on a single frame (still
image) inpainting. Exemplar-based approach uses patches from the known areas and copies their content
to the damaged area.../...
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Film Grain Synthesis and its Application to Re-graining
Digital film restoration and special effects compositing require more and more automatic procedures for movie regraining.
Missing or inhomogeneous grain decreases perceived quality. For the purpose of grain synthesis an existing
texture synthesis algorithm has been evaluated and optimized. We show that this algorithm can produce synthetic grain
which is perceptually similar to a given grain template, which has high spatial and temporal variation and which can be
applied to multi-spectral images.../...
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The proposed deinterlacing scheme is aimed towards high-quality progressive image output, typically for a videotape-to-film blow-up operation. This operation consists in increasing the resolution of video images, recording these images on 16mm or 35mm film and reducing the typical video artefacts (due to interlaced scanning, electronic noise), eventually adding some film-look features (color correction, motion blur,...) .../...
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Two algorithms for movie sound tracks restoration are discussed in the paper. The first algorithm is the unpredictability measure computation applied to the psychoacoustic model-based broadband noise attenuation. A learning decision algorithm, based on a neural network, is employed for determining useful audio signal components acting as maskers of the noisy spectral parts. An application of the rough set decision system to this task is also considered. An iterative method for calculating the sound masking pattern is presented. The second of presented algorithms is the routine for precise evaluation of parasite frequency modulations (wow) utilizing sinusoidal components extracted from the sound spectrum. The results obtained employing proposed intelligent signal processing algorithms, as well as the relationship between both routines, will be presented and discussed in the paper.
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The Unpredictability Measure computation algorithm applied to psychoacoustic model-based broadband noise attenuation is discussed. A learning decision algorithm based on a neural network is employed for determining audio signal useful components acting as maskers of the spectral components classified as noise. An iterative algorithm for calculating the sound masking pattern is presented.../...
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New algorithm for detection of the wow distortion characteristic basing on the MTS pilot tracking is introduced. By observing a variation of the pilot frequency, the depth of the parasitic modulation can be estimated. MTS is an audio coding system used in an NTSC television standard, thus the algorithm is applicable only in that type of recordings. It is based on a high-frequency bias tracking algorithm and further modified to minimize the influence of an acoustic-band audio signals which may interfere with the 15.734 kHz MTS pilot tone.
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Several methods devoted to wow defect evaluation and compensation are discussed in the paper. The presented algorithms utilize time- and spectrally-based audio processing routines. The newly proposed time-domain algorithm takes an advantage of an autocorrelation analysis of short-term pitch variations. The spectrally based methods employ: spectral peak picking techniques, analysis of spectral center of gravity, and some routines for tracking high-frequency bias in magnetic recordings.../...
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New algorithms were developed for discriminating wow from natural musical effects, such as: periodicity detection by means of autocorrelation signal, algorithm employing AR model for power line hum frequency detection and algorithm for estimating pitch variation curve employing wow tracking based on recording bias detection in magnetic recordings. Moreover. non-uniform resampling routine was implemented and applied to wow compensation. The developed algorithms were studied using real audio examples allowing a comparison of their effectiveness.
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A novel non-motion-compensated method is proposed for dirt detection in archived film sequences. A confidence measurement extracted from raw differences between current frame and each of the previous and next frames is used to exploit the temporally impulsive nature of dirt impairments.../...
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On missing Data Recovery of Dirt Sparkles from Degraded Colour Films
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The knowledge of material specific film grain characteristics can significantly improve the performance of digital film processing algorithms. This paper proposes a rapid and reliable detector for film grain properties. First, homogeneous blocks concerning intensity and texture are determined by a novel measure calculated in the frequency domain. Second, based on these blocks the signal-dependent grain noise level is estimated and an image region of pure film grain is detected.
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Poster session IMA (Institute for Mathematics and Application)
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A novel segmentation-assisted method for film dirt detection is proposed. We exploit the fact that film dirt manifests in the spatial domain as a cluster of connected pixels whose intensity differs substantially from that of its neighborhood and we employ a segmentation-based approach to identify this type of structure.
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A novel segmentation-assisted method for film dirt detection is proposed. Since dirt manifests as a cluster of pixels whose intensity differs from that of its neighbourhood, we employ segmentation and assume that each small region as a dirt candidate. The assumption is validated by considering raw (non-motion compensated) differences between the current frame and each of the previous and next frames which provides a measure of a confidence.../...
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This paper presents an adaptation of the exemplar-based inpainting process for image sequences. The aimed application
is digital restoration of old movies, and particularly scratch removal, which still remains an unsolved problem .../...
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Ten years of Visual Restoration Systems,
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In this paper the capacity of different interpolation techniques aimed at wow defect reduction is examined. Involved are: linear interpolation, two polynomial based interpolation methods (Hermite and spline) and the windowed sinc-based method. The performance of a synthetic audio signal restored using incommensurate resampling for wow cancellation is evaluated on the basis of standard audio defect measurement criteria and compared for four interpolation techniques.
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In this paper the capacity of different interpolation techniques aimed at wow defect reduction is examined. Involved are: linear interpolation, two polynomial based interpolation methods (Hermite and spline) and the windowed sinc-based method. The performance of a synthetic audio signal restored using incommensurate resampling for wow cancellation is evaluated on the basis of standard audio defect measurement criteria and compared for four interpolation techniques.
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The engineered algorithms are presented for the detection of parasitic frequency modulation in audio originating from irregularities of sound carrier velocity. The algorithms were developed with special regard to non-periodic frequency modulation effects found in old movie sound tracks. The proposed algorithms consider the influence of the wow disturbance on the location of formants in time-frequency representation.../...
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2 Wiki Pages
Restoration algorithms and tools; System integration
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An index of the PrestoSpace work that explains or develops digital technology relevant to audiovisual collections.
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A Virtual Lifesaver
Network Computing Magazine | Storage and Servers Channel: Features, Reviews, Commentary and more
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