Iterative Wavefront Reconstruction for Ptychographic Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for generating image data from target objects, such as those using Ptychographical Iterative Engines (PIE), face challenges in achieving high resolution and convergence rate while minimizing noise, particularly in estimating wave fronts and probe functions.
Innovation Solution
The method involves positioning the aperture or incident radiation in a way that a larger portion of the estimated wave front remains unchanged, with a smaller portion updated based on detected radiation, and iteratively re-estimating both the object and probe functions, using a diffuser to reduce dynamic range and enhance image data fidelity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a larger portion of the wave front is updated based on detected radiation, then measurement precision improves, but noise in image data increases and convergence rate decreases
Solution Approach 1:
The patent applies local quality by differentiating the treatment of different regions of the wave front. The central region is updated with measured diffraction data while peripheral regions are constrained or set to predetermined values. This localized differential approach allows the most critical regions to contribute to image resolution while less critical regions are controlled to minimize noise propagation, thereby resolving the contradiction between measurement precision and noise reduction.
2Measurement precision
If more diffraction patterns are recorded to improve image resolution, then measurement precision improves, but the time required for data acquisition and processing increases
Solution Approach 1:
The patent segments the wave front into multiple regions (central and peripheral) and processes them differently during the iterative reconstruction. This segmentation allows the algorithm to efficiently utilize the available diffraction data by focusing computational resources on the central region that provides the most information for image resolution, while applying constraints to peripheral regions. This reduces the effective computational burden and can accelerate convergence without sacrificing resolution.
Solution Approach 2:
The patent implements partial action by updating only a portion of the wave front (the central region) with measured data while constraining other portions. This partial update strategy prevents the algorithm from being overwhelmed by the full complexity of all diffraction data, thereby reducing processing time while still achieving high-resolution reconstruction through the informative central region.
3Measurement precision
If the probe function is iteratively recalculated to improve image accuracy, then measurement precision improves, but the complexity of the computational process increases
Solution Approach 1:
The patent reduces computational complexity by applying local quality principles to the probe function updates. Instead of uniformly updating the entire probe function across all regions, the method focuses iterative refinement on the central region where the probe function has the greatest impact on image accuracy. Peripheral regions of the probe function are constrained or updated less frequently, significantly reducing the computational burden while maintaining high image accuracy through the critical central region refinement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach improves image resolution and convergence rate while reducing noise in the image data, allowing for more accurate representation of diffraction patterns and minimizing damage to the target object.
Implementation Method 1
Some embodiments of the invention utilise a diffuser to reduce a dynamic range of scattered radiation
Implementation Method 2
An intensity of radiation scattered by the target object is detected using at least one detector
Data Source
Figure 1~2
Figure 3
Figure 4(a)~4(b)
AI summary
Embodiments of the present invention provideamethod of providing image data for constructing an image of a region of a target object, comprising providing incident radiation from a radiation source at a target object;detecting, by at least one detector, a portion of radiation scattered by the target object; and providing image data via an iterative process responsive to the detected radiation, wherein said iterative process comprises estimating a wave front of scattered radiation at a plane of the detector, updating a portion of the wave front based on the detected radiation, leaving a portion of the estimated wave front substantially unchanged, setting a portion of the wave front, corresponding to a portion of radiation scattered by the target object and not detected by the detector, to one or more values, and providing image data based upon the updated wave front.