Microlens array calibration method for a light field camera

Suliga, Piotr; Wrona, Tomasz

doi:10.1109/carpathiancc.2018.8399595

Cited by 5 publications

(5 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First, the Micro-Images Array has to be calibrated. We compute the micro-image centers observations {c k,l } by intensity centroid method with sub-pixel accuracy [30,20,28]. The distance between two micro-image centers δc is then computed as the optimized edge-length of a fitted 2D grid mesh with a non-linear optimization.…”

Section: Features Extractionmentioning

confidence: 99%

Blur Aware Calibration of Multi-Focus Plenoptic Camera

Labussière

Teulière

Bernardin

et al. 2020

2020 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)

View full text Add to dashboard Cite

This paper presents a novel calibration algorithm for Multi-Focus Plenoptic Cameras (MFPCs) using only raw images. The design of such cameras is usually complex and relies on precise placement of optic elements. Several calibration procedures have been proposed to retrieve the camera parameters but relying on simplified models, reconstructed images to extract features, or yet multiple calibrations when several types of micro-lens are used. Considering blur information, we propose a new Blur Aware Plenoptic (BAP) feature. It is first exploited in a pre-calibration step that retrieves initial camera parameters, and secondly to express a new cost function for our single optimization process. The effectiveness of our calibration method is validated by quantitative and qualitative experiments.

show abstract

Section: Features Extractionmentioning

confidence: 99%

Blur Aware Calibration of Multi-Focus Plenoptic Camera

Labussière

Teulière

Bernardin

et al. 2020

2020 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)

View full text Add to dashboard Cite

show abstract

“…Fortunately, due to the overall formulation of the intrinsics as an end-to-end ray transformation, this slight change is not relevant for the calibration results, as neither f m nor d is directly estimated. Instead, the factor M proj contributes to the intrinsic variables H 1,1 to H 4,4 , and repeating the deduction of H with the correct scaling leads to the same general form for the intrinsics matrix as in Equation (23).…”

Section: Light Field Decoding and Spc Calibrationmentioning

confidence: 99%

“…Using a similar model, Zhao et al [ 21 ] performed SPC calibration based on the plenoptic disc features. Both Thomasen et al [ 22 ] and Suliga and Wrona [ 23 ] directly estimated the MLA pose and microlens pitch; however, neither related the captured light field to the scene-side light field. Similar to the approaches related to [ 7 ], these works assume the microlens images centers to be projections of the main lens center, i.e., the center of the camera-side principal plane.…”

Section: Introductionmentioning

confidence: 99%

Mind the Exit Pupil Gap: Revisiting the Intrinsics of a Standard Plenoptic Camera

Michels,

Mäckelmann,

Koch

2024

Sensors

View full text Add to dashboard Cite

Among the common applications of plenoptic cameras are depth reconstruction and post-shot refocusing. These require a calibration relating the camera-side light field to that of the scene. Numerous methods with this goal have been developed based on thin lens models for the plenoptic camera’s main lens and microlenses. Our work addresses the often-overlooked role of the main lens exit pupil in these models, specifically in the decoding process of standard plenoptic camera (SPC) images. We formally deduce the connection between the refocusing distance and the resampling parameter for the decoded light field and provide an analysis of the errors that arise when the exit pupil is not considered. In addition, previous work is revisited with respect to the exit pupil’s role, and all theoretical results are validated through a ray tracing-based simulation. With the public release of the evaluated SPC designs alongside our simulation and experimental data, we aim to contribute to a more accurate and nuanced understanding of plenoptic camera optics.

show abstract

“…First, the micro-images array (MIA) is calibrated using raw white images. We compute the micro-image centers c c c k,l by the intensity centroid method with sub-pixel accuracy (Thomason et al, 2014;Noury et al, 2017;Suliga et al, 2018). The distance between two micro-image centers δ i is then computed as the optimized edge-length of a fitted 2D regular grid mesh.…”

Section: Micro-images Array Calibrationmentioning

confidence: 99%

Leveraging blur information for plenoptic camera calibration

Labussière,

Teulière,

Bernardin

et al. 2021

Preprint

View full text Add to dashboard Cite

This paper presents a novel calibration algorithm for plenoptic cameras, especially the multi-focus configuration, where several types of micro-lenses are used, using raw images only. Current calibration methods rely on simplified projection models, use features from reconstructed images, or require separated calibrations for each type of micro-lens. In the multi-focus configuration, the same part of a scene will demonstrate different amounts of blur according to the micro-lens focal length. Usually, only micro-images with the smallest amount of blur are used. In order to exploit all available data, we propose to explicitly model the defocus blur in a new camera model with the help of our newly introduced Blur Aware Plenoptic (BAP) feature. First, it is used in a pre-calibration step that retrieves initial camera parameters, and second, to express a new cost function to be minimized in our single optimization process. Third, it is exploited to calibrate the relative blur between micro-images. It links This work was supported by the AURA Region and the European Union (FEDER) through the MMII project of CPER 2015-2020 MMaSyF challenge.

show abstract

Microlens array calibration method for a light field camera

Cited by 5 publications

References 6 publications

Blur Aware Calibration of Multi-Focus Plenoptic Camera

Blur Aware Calibration of Multi-Focus Plenoptic Camera

Mind the Exit Pupil Gap: Revisiting the Intrinsics of a Standard Plenoptic Camera

Leveraging blur information for plenoptic camera calibration

Contact Info

Product

Resources

About