Synchronization and rolling shutter compensation for consumer video camera arrays

Bradley, Derek; Atcheson, Bradley; Ihrke, Ivo; Heidrich, Wolfgang

doi:10.1109/cvprw.2009.5204340

Cited by 45 publications

(15 citation statements)

References 15 publications

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“…However, we can easily set a distance within a 100-pixel offset within five trials for each camera. Therefore, we could easily control the accuracy of our synchronization within

54 sans-serifμ normals \times 100 = 5.4

ms, much less than the frame-level (41.7 ms) synchronization [24,25]. We can achieve more accurate synchronization if the 100-pixel offset distance for each camera is reduced even further with more trials.…”

Section: Resultsmentioning

confidence: 99%

Stroboscope Based Synchronization of Full Frame CCD Sensors

Shen

Feng

Zhang

et al. 2017

Sensors

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The key obstacle to the use of consumer cameras in computer vision and computer graphics applications is the lack of synchronization hardware. We present a stroboscope based synchronization approach for the charge-coupled device (CCD) consumer cameras. The synchronization is realized by first aligning the frames from different video sequences based on the smear dots of the stroboscope, and then matching the sequences using a hidden Markov model. Compared with current synchronized capture equipment, the proposed approach greatly reduces the cost by using inexpensive CCD cameras and one stroboscope. The results show that our method could reach a high accuracy much better than the frame-level synchronization of traditional software methods.

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“…However, we can easily set a distance within a 100-pixel offset within five trials for each camera. Therefore, we could easily control the accuracy of our synchronization within

54 sans-serifμ normals \times 100 = 5.4

Section: Resultsmentioning

confidence: 99%

Stroboscope Based Synchronization of Full Frame CCD Sensors

Shen

Feng

Zhang

et al. 2017

Sensors

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“…We adopt a rolling shutter camera model similar to the one of Bradley et al [3]. Figure 3 illustrates the capturing process within this model.…”

Section: Camera Modelmentioning

confidence: 99%

“…This problem is only aggravated with the use of low cost high speed cameras, so that switching lights on and off with a frequency close to the frame rate of the camera becomes impractical. To overcome the limitations of rolling shutter cameras, Theobalt et al [30] have used stroboscopic lighting to capture high speed motion of a baseball using standard still cameras and high power stroboscope, and Bradley et al [3] have used stroboscopic light to synchronize an array of consumer grade cameras. In [14], Kim et al used infrared leds tied to a simple independent timer to synchronize eye and scene image streams manually.…”

Section: Stroboscopic Structured Lightingmentioning

confidence: 99%

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A Fast and Accurate Eye Tracker Using Stroboscopic Differential Lighting

Borsato

Aluani

Morimoto

2015

2015 IEEE International Conference on Computer Vision Workshop (ICCVW)

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The use of video-based eye trackers (VETs) for gaze interaction have allowed people with severe motor disabilities to communicate more effectively. Nonetheless, current low cost VETs present limited accuracy and precision that impose several design constraints for gaze-based computer applications. In this paper we present an extension of the differential lighting (DL) technique for pupil detection and tracking using active light sources. The original technique was developed for analog interlaced cameras with external sync signal to synchronize the light sources with the video signal. In this paper we introduce the Stroboscopic DL technique that can be used with any rolling shutter camera, even those with no external sync. We have developed a computer vision technique to adjust the firing of the stroboscopic lights. Our new algorithm also exploits characteristics of pupil images to improve the accuracy of the tracking algorithm. Another advantage of the method is that using flashed pulses of light creates a virtual exposure time, reducing motion blur and temporal shear in the video volume. A real-time 187 fps prototype of the system was implemented using a low cost PS3 camera. Experimental results comparing the performance of our algorithm with Starburst show significant accuracy and speed improvement.

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“…The advantages of this simple approach over either a setup based on an object on a turntable using a single camera [8,11], or a still object using multiple cameras [4,12] are the following: [3]. Note also that use of multiple cameras and a networking procedure is also an expensive solution.…”

Section: Introductionmentioning

confidence: 97%

High-throughput 3D modelling of plants for phenotypic analysis

Kumar

Cai

Miklavcic

2012

Proceedings of the 27th Conference on Image and Vision Computing New Zealand

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In this paper we propose a twin mirror-based system for reconstructing 3D models of real plants for subsequent phenotypic analysis. The method is based on the visual hull concept: multiple reflections of the object from the mirrors give different views of the object and are interpreted as taken from virtual cameras. The epipolar geometry of the object and its four reflections is determined without relying on information of the positions of the camera and mirrors. This alleviates the usual camera calibration step. Two simultaneous images of object mirror scene give ten different and simultaneous views of the plant, without requiring any plant or camera movement. Visual hull algorithms are sensitive to segmentation of the object from the scene. We propose a novel machine learning approach to segment a plant from its background. The plant colours are represented using a Gaussian mixture model (GMM), while the background colours are represented by a separate GMM, learnt using an Expectation Maximisation (EM) algorithm. A Bayes classification rule that satisfies the Neymann-Pearson criteria is used to classify the pixels and thus segment the five plant silhouette from each image. We show results of 3D models of wheat, grass, and a lavender shoot reconstructed using the proposed segmentation and 3D visual hull method.

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Synchronization and rolling shutter compensation for consumer video camera arrays

Cited by 45 publications

References 15 publications

Stroboscope Based Synchronization of Full Frame CCD Sensors

Stroboscope Based Synchronization of Full Frame CCD Sensors

A Fast and Accurate Eye Tracker Using Stroboscopic Differential Lighting

High-throughput 3D modelling of plants for phenotypic analysis

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