The present disclosure relates to apparatuses and methods for performing in-line lens-free digital holography of objects. At least one embodiment relates to an apparatus for performing in-line lens-free digital holography of an object. The apparatus includes a point light source adapted for emitting coherent light. The apparatus also includes an image sensing device adapted and arranged for recording interference patterns resulting from interference from light waves directly originating from the point light source and object light waves. The object light waves originate from light waves from the point light source that are scattered or reflected by the object. The image sensing device comprises a plurality of pixels. The point light source comprises a broad wavelength spectrum light source and a pinhole structure. The image sensing device comprises a respective narrow band wavelength filter positioned above each pixel that filters within a broad wavelength spectrum of the point light source.

Provided is an apparatus and method for generating a hologram pattern with a reduced amount of computation. The apparatus may include a reference depth layer setting unit configured or having a capacity to set a reference depth layer using data associated with a three-dimensional (3D) object, a first hologram pattern generating unit configured to generate a first hologram pattern corresponding to the 3D object in the reference depth layer, and a second hologram pattern generating unit configured to generate a second hologram pattern in a hologram plane using the first hologram pattern.

An imaging module of a projection device generates a multi-color image such that a first color sub-image with a first wavelength and a second color sub-image with a second wavelength are generated. Deflection efficiency curves for a specified angular range about a specified viewing angle are set such that a first efficiency ratio for the specified angular range is constant. The imaging module is actuated such that when the multi-color image is generated, a first brightness ratio of the brightness of the first color sub-image to the brightness of the second color sub-image is inversely proportional to the a efficiency ratio such that different deflection efficiency curves are compensated for and such that the viewer can perceive the multi-color image as a true-color virtual image at viewing angles from the specified angular range.

The present disclosure relates to apparatuses and methods for performing in-line lens-free digital holography of objects. At least one embodiment relates to an apparatus for performing in-line lens-free digital holography of an object. The apparatus includes a point light source adapted for emitting coherent light. The apparatus also includes an image sensing device adapted and arranged for recording interference patterns resulting from interference from light waves directly originating from the point light source and object light waves. The object light waves originate from light waves from the point light source that are scattered or reflected by the object. The image sensing device comprises a plurality of pixels. The point light source comprises a broad wavelength spectrum light source and a pinhole structure. The image sensing device comprises a respective narrow band wavelength filter positioned above each pixel that filters within a broad wavelength spectrum of the point light source.