Patent No. US12117403 (titled "Gemstone Planning") was filed by De Beers Uk Ltd on May 21, 2020.
’403 is related to the field of gemstone cutting and planning, specifically optimizing the yield and quality of a faceted gemstone cut from a rough gemstone. Traditionally, this process involves creating detailed 3D models of both the rough stone and the target cut, which requires significant computational resources. The background highlights the need for efficient methods to determine the best possible cut while minimizing waste and maximizing the value of the final gemstone.
The underlying idea behind ’403 is to streamline the gemstone planning process by using 2D silhouette images for comparison instead of directly manipulating complex 3D models. The core insight is that by comparing 2D projections of the rough stone and the target cut, one can efficiently determine the optimal orientation, scale, and position of the target cut within the rough stone, thereby reducing the computational burden.
The claims of ’403 focus on a method and apparatus for determining the optimal target gemstone obtainable from a rough gemstone. This involves capturing a series of 2D silhouette images of the rough gemstone, generating a corresponding series of virtual 2D silhouette images from a 3D model of the desired target gemstone, and then comparing these two series of images to find the optimal transformation (rotation, translation, and scaling) to apply to the 3D model of the target gemstone.
In practice, the method involves illuminating the rough gemstone with collimated light and capturing silhouette images from various angles. A 3D model of the target gemstone is then virtually projected from the same angles to create corresponding silhouette images. The system then iteratively adjusts the scale, rotation, and position of the target gemstone's virtual silhouette until it finds the largest possible target gemstone that fits within the rough stone's silhouette, effectively maximizing yield.
This approach differentiates itself from prior methods by avoiding direct 3D model manipulation during the optimization process. Instead of computationally intensive 3D comparisons, the system compares 2D silhouette images, significantly reducing the processing power required. The method also uses a binary search-like approach with scaling factors (S1 and S2) to efficiently converge on the optimal scale , further enhancing the speed and efficiency of the gemstone planning process.
In the late 2010s when ’403 was filed, at a time when 3D modeling was typically implemented using a combination of specialized hardware and software, systems commonly relied on capturing multiple 2D images from different viewpoints to construct a 3D representation, and when hardware or software constraints made real-time processing of complex 3D models non-trivial.
The examiner approved the claims because the prior art, specifically Sivovolenko, does not teach comparing a first series of 2D silhouette images and a second series of virtual 2D silhouette images to determine an optimal transformation to be applied to the 3D model of the target gemstone. While other references teach individual aspects of the claimed invention, they do not disclose this specific combination of elements.
This patent contains 21 claims, with independent claims 1, 19, and 21. The independent claims focus on methods and an apparatus for determining an optimal target gemstone obtainable from a rough gemstone by comparing 2D silhouette images of the rough gemstone with virtual 2D silhouette images of a target gemstone. The dependent claims generally elaborate on and refine the methods described in the independent claims, adding details regarding image acquisition, correlation, scaling, and transformation processes.
Definitions of key terms used in the patent claims.

The dossier documents provide a comprehensive record of the patent's prosecution history - including filings, correspondence, and decisions made by patent offices - and are crucial for understanding the patent's legal journey and any challenges it may have faced during examination.
Date
Description
Get instant alerts for new documents