Despite many years of development in computer-generated holography, perfect phase-only holograms for most target images are still yet possible to compute. All computational phase retrieval algorithms end up with some error between the image and reconstruction hologram (CGH), except specific targets. This research focuses on fundamental limits CGH quantized limited bit-depth levels, from information theory point view, revealing capacity its effect quality, an attempt quantify how hard a is...

We implement a limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) optimization of phase-only computer-generated hologram for multi-depth three-dimensional (3D) target. Instead computing the full 3D reconstruction hologram, we use novel method using L-BFGS with sequential slicing (SS) partial evaluation during that only computes loss single slice at every iteration. demonstrate its ability to record curvature information enables have good quality imbalance suppression under SS technique.

Abstract Understanding and improving the perceived quality of reconstructed images is key to developing computer-generated holography algorithms for high-fidelity holographic displays. However, current are typically optimized using mean squared error, which widely criticized its poor correlation with perceptual quality. In our work, we present a comprehensive analysis employing contemporary image metrics (IQM) as loss functions in hologram optimization process. Extensive objective subjective...

SGD (Stochastic gradient descent) is an emerging technique for achieving high-fidelity projected images in CGH (computer-generated holography) display systems. For real-world applications, the devices to corresponding holographic fringes have limited bit-depth depending on specific technology employed. performance adversely affected by this limitation and piece of work we quantitatively compare impact algorithmic based different bit-depths developing our own algorithm, Q-SGD (Quantised-SGD)....

Spatial light modulators (SLMs) are key research tools in several contemporary applied optics domains. In this paper, we present the argument that an open platform for interacting with SLMs would dramatically increase their accessibility to researchers. We introduce HoloBlade, open-hardware implementation of SLM driver-stack, and provide a detailed exposition HoloBlade’s architecture, components, design. An optical verification rig is constructed demonstrate HoloBlade can Fourier imaging...

In a computer-generated holographic projection system, the image is reconstructed via diffraction of light from spatial modulator. this process, several factors could contribute to non-linearities between reconstruction and target image. This paper evaluates non-linearity overall system experimentally, using binary phase holograms computed one-step retrieval (OSPR) algorithm, then applies digital pre-distortion (DPD) method correct for non-linearity. Both notable increase in quality...

The generation of computer-generated holograms (CGHs) requires a significant amount computational power. To accelerate the process, highly parallel field-programmable gate arrays (FPGAs) are deemed to be promising computing platform implement non-iterative hologram algorithms. In this paper, we present cost-optimized heterogeneous FPGA architecture based on one-step phase retrieval algorithm for CGH generation. results indicate that our hardware implementation is 2.5× faster than equivalent...

We implement a novel limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) optimisation algorithm with cross entropy (CE) loss function, to produce phase-only computer-generated hologram (CGH) for holographic displays, validation on binary-phase modulation projector.

Computer Generated Holograms (CGHs) are fundamental to the creation of holographic display and responsible for carrying phase or amplitude information a particular optical field. The standard approaches CGH generation on personal computers all involve multiple forward inverse 2-dimensional fast Fourier Transforms (2D FFTs). This common method is not enough real-time application. Producing CGHs via configurable hardware may reduce computational burden. To overhead, fixed-point arithmetic...

The Kaczmarz algorithm is an iterative method for solving linear equations in the form of Ax = b. It widely used computed tomography and digital signal processing (DSP) but has yet to be adopted computer-generated holography. Phase retrieval algorithms, such as Gerchberg–Saxton or Fienup, are significantly more popular this field. However, we propose a unique alternative approach projecting replay field through discrete Fourier transform matrices have shown that there legitimate benefits...

We introduce a concurrent real-time calibration process for diffractive lithography using liquid crystal spatial light modulators. This allows increased power handling capabilities given phase modulation accuracy.

The effects of time-varying measurement noise on transmission matrix acquisition processes are considered for the first time, to our knowledge. Dominant sources discussed, and properties a typical interferometer system used characterizing multimode fiber quantified. It is demonstrated that an appropriate choice basis allows more accurate be quickly obtained in presence noise. Finally, it shown figure experimental inverse constructed with ideal amount regularization, which can turn optimal...

We present a method to create the holographic foveated rendering effect based on iterative phase retrieval algorithm. validated our proposing algorithm using an optical setup with multi-phase spatial light modulator.

We present a DST-based Gerchberg-Saxton search algorithm for generating binary-phase holograms. The new is shown to give an order of magnitude speed improvement small reduction in image quality.

We combine a continuous feedback hardware-in-the-loop approach with binary-phase SLM and an imaging sensor to produce computer-generated holography system which is scalable in cost, tolerant real-world effect suitable for mass-market adoption.

We present an implementation of the One-Step Phase-Retrieval (OSPR) algorithm for computer-generated holography (CGH) using a digital signal processor (DSP). Typically, personal computers with powerful graphics processing units and field programmable gate arrays are used hologram generation. Such systems, however, high-cost usually not suitable embedded applications. use Texas Instrument TMDXEVM6678LE evaluation module carrying TMS320C6678 eight-core DSP to evaluate performance. implement...

We present HoloBlade, a collection of open and accessible technologies to advance the field holography serve wider research community. The initial implementation is presented functionality demonstrated.

We present a hardware architecture for generating Fresnel holograms 3D holography on small scale field-programmable gate arrays. Our implementation can achieve similar performance to high-end CPU enabled software implementation.

A traditional limitation of holographic displays has been their image quality. Recent advances in computer-generated holography using a camera-in-the-loop (CITL) approach have demonstrated that these issues can be overcome to improve image-fidelity by treating the system as negative feedback control loop. Such an demands high bit-depth camera sensors realise bandwidth. Here, we explore boosting dynamic-range given imaging sensor spatially varying exposure (SVE) approach. The levels adjacent...

In a computer-generated holographic projection system, the image is reconstructed via diffraction of light from spatial modulator. this process, several factors could contribute to non-linearities between reconstruction and target image. This paper evaluates non-linearity overall system experimentally, using binary phase holograms computed one-step retrieval (OSPR) algorithm, then applies digital pre-distortion (DPD) method correct for non-linearity. Both notable increase in quality...

The Cimmino algorithm is an iterative used for solving linear equations ( Ax = b ) and part of a wider family algebraic reconstruction algorithms. Despite being in computed tomography digital signal processing, we present approach using it holographic projections the Fraunhofer region. Following work carried out by our group on Kaczmarz holography, earlier equation solver, compare performance speed against this algorithm. Three versions algorithm, full, eye, FFT, are evaluated compared to...

We implement a novel limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) optimisation algorithm with cross entropy (CE) loss function, to produce phase-only computer-generated hologram (CGH) for holographic displays, validation on binary-phase modulation projector.

We propose a scheme for free-space optoelectronic element-wise multiplications, the Symbolic Encoding Scheme. The formation and processes related to are discussed, followed by an optical setup experimentally demonstrate practicability.