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Light Field Stitching with a Plenoptic Camera. Zhou Xue LCAV - École Polytechnique Fédérale de Lausanne Dec . 2 201 3. Overview. What is Plenoptic Function Light field stitching for artwork acquisition Revisit the image stitching Light field sample by a plenoptic camera
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Light Field Stitchingwith a PlenopticCamera Zhou Xue LCAV - École Polytechnique Fédérale de Lausanne Dec. 2 2013
Overview • What is Plenoptic Function • Light field stitching for artwork acquisition • Revisit the image stitching • Light field sample by a plenoptic camera • Light field stitching by camera translations and rotations • Following work
Overview • What is Plenoptic Function • Light field stitching for artwork acquisition • Revisit the image stitching • Light field sample by a plenoptic camera • Light field stitching by camera translations and rotations • Following work
The Light Field of an Oil Painting RGB or Multi-spectral image Video or image (θ, Φ) (x, y, z) • Camera location (x, y, z) • View direction (θ, Φ) • Wavelength and time
Light Field of the Oil Painting • Capture the oil painting at different camera plane image plane v Camera plane x
Overview • What is Plenoptic Function • Light field stitching for artwork acquisition • Revisit the image stitching • Light field sample by a plenoptic camera • Light field stitching by camera translations and rotations • Following work
Light Field Stitching • Framework: • Set up a X-Y table with accurate translations • Registering the light field from each sample • Stitching and interpolating a new light field • Challenges: • Sampling pattern of POC • Registration problem • How to create the virtual light field
Understand Image Stitching in the Light Field • Image Stitching with camera rotations • Image Stitching with camera translations
Overview • What is Plenoptic Function • Light field stitching for artwork acquisition • Revisit the image stitching • Light field sample by a plenoptic camera • Light field stitching by camera translations and rotations • Following work
Light Field Sample of a Plenoptic Camera • A simplified model of the plenoptic camera: • Main lens + moving pinhole camera aL bL tM vM
Light Field Sample of a Plenoptic Camera • Samples from the moving pinhole camera v t = t + v·aL Image on the conjugate plane Light rays propagate to the actual camera plane
Light Field Sample of a Plenoptic Camera • Light field image example
Light Field Sample of a Plenoptic Camera • Light field image example
Overview • What is Plenoptic Function • Light field stitching for artwork acquisition • Revisit the image stitching • Light field sample by a plenoptic camera • Light field stitching by camera translations and rotations • Following work
Light Field Stitching by Camera Translations • Comparison between image stitching and light field stitching by camera translations
Light Field Stitching by Camera Rotations • Comparison between image stitching and light field stitching by camera rotations
Light Field Stitching by Camera Rotations • Comparison between image stitching and light field stitching by camera rotations
Light Field Stitching for Increasing Angular Range • Light field stitching by combining translation and rotation • Enlarge the main lens of the plenoptic camera • Directly stitch the pinhole camera image
Light Field Stitching for Increasing Angular Range • One example for acquisition of surface light field • Main lens focus on the flat surface • Each pinhole image relates the BRDF of a pigment
Revisit the Light Field of an Oil Painting -1/aL • Vertical line represents the image taken on plane t • Horizontal line represents the image taken at infinity • Green line represents the image taken at plane aL
Light Field Stitching for Increasing Spatial Range • Light field re-sample to generate panorama image from a virtual camera behind the camera plane
Preliminary Results of Light Field Stitching • Panorama image from multiple light field images Main lens: (unit: meters) Lens radiance = 10*1.0e-2; Focal length = 10*1.0e-3; Micro lens array (MLA): Radiance of MLA= 60*1.0e-3; Samples on MLA=15; Sensor of the moving pinhole camera: Sensor radiance =1*1.0e-4; Samples on the sensor=11; Scene: Distance of the center= 0.2; Slanted angle = 3 degree; Stitching parameters: LF image samples =41×41; LF image size(u, v, x, y)=11×11×15×15 Stitched image size =451×451
Overview • What is Plenoptic Function • Light field stitching for artwork acquisition • Revisit the image stitching • Light field sample by a plenoptic camera • Light field stitching by camera translations and rotations • Following work
Following Work • Work with plenoptic camera (Lytro and Raytrix) • Light field stitching experiments • Stitching with camera translation or rotation • Extend angular range by combining camera motions • Extend spatial range by re-sampling the light field • Derive the theoretical boundary for the stitched light field • Maximum angular and spatial range • Maximum angular and spatial resolution