Method, system, and computer program for performing appearance quality assessment using holographic interferometry

Abstract

To provide a method, system and computer program for performing visual quality assessment employing holographic interferometry.SOLUTION: Aspects of the invention include obtaining a reference holographic pattern based on a reference object, and obtaining a test holographic pattern based on a test object. The aspects also include creating an interference pattern by superimposing the test holographic pattern on the reference holographic pattern. The aspects further include determining a difference between the reference object and the test object based on the interference pattern.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates generally to appearance quality assessment, and more particularly to enhancing appearance quality assessment using holographic interferometry. [Background technology]

[0002] Manufacturers often need to perform visual inspections of manufactured objects to ensure that the quality of the objects meets the desired fault tolerance. Currently, various artificial intelligence (AI) vision-based systems are used to perform these visual assessments. These tools utilize neural network vision model training to perform object detection and image classification operations on visual data, such as still images or video, or a combination of both. Performing these operations on optical data requires significant computing resources, such as memory, CPU, and GPU cycles. Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention aims to provide a method, system, and computer program for performing appearance quality assessment using holographic interferometry. [Means for solving the problem]

[0004] According to one embodiment, a system for performing appearance quality assessment using holographic interferometry is provided, the system comprising a memory having computer-readable instructions and a processor for executing the computer-readable instructions, the computer-readable instructions comprising: a reference object based on the reference object; Ta Obtaining a reference holographic pattern based on the test object TaThe computer-readable instructions also include instructions for obtaining a test holographic pattern by overlaying the test holographic pattern onto the reference holographic pattern. a difference representing the difference between the test holographic pattern and the reference holographic pattern pattern (Hereinafter, this will be referred to as "interference pattern") The computer readable instructions further include instructions for determining a difference between the reference object and the test object based on the interference pattern.

[0005] According to another embodiment, a method is provided for performing appearance quality assessment using holographic interferometry, the method comprising: Ta Obtaining a reference holographic pattern based on the test object Ta The method includes acquiring a test holographic pattern. The method also includes generating an interference pattern by superimposing the test holographic pattern on the reference holographic pattern. The method further includes determining a difference between the reference object and the test object based on the interference pattern.

[0006] According to a further embodiment, a computer program product is provided. The computer program product includes a computer-readable storage medium having program instructions embodied thereon, the computer-readable storage medium being not a transitory signal itself. The program instructions are executable by a computer processor to cause the computer processor to perform a method, the method being based on a reference object. Ta Obtaining a reference holographic pattern based on the test object Ta The method includes acquiring a test holographic pattern. The method also includes generating an interference pattern by superimposing the test holographic pattern on the reference holographic pattern. The method further includes determining a difference between the reference object and the test object based on the interference pattern.

[0007] Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the present invention, together with its advantages and features, reference should be made to the detailed description and drawings of the invention. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 illustrates a cloud computing environment in accordance with one or more embodiments of the present invention. [Figure 2] FIG. 1 illustrates abstraction model layers in accordance with one or more embodiments of the present invention. [Figure 3] FIG. 1 illustrates an exemplary computer system in which one or more embodiments of the present invention may be implemented. [Figure 4] 1 is a schematic diagram of a system for capturing a holographic pattern of an object in accordance with one or more embodiments of the present invention. [Figure 5] 1A-1C illustrate various examples of interference patterns in accordance with one or more embodiments of the present invention. [Figure 6] FIG. 1 is a flow diagram of a method for performing appearance quality assessment using holographic interferometry in accordance with one or more embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims appended hereto. The foregoing and other features and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0010] Various embodiments of the present invention are described herein with reference to the associated drawings. Alternate embodiments of the present invention may be devised without departing from the scope of the present invention. The following description and drawings describe various connections and relationships (e.g., above, below, adjacent, etc.) between elements. These connections and / or relationships may be direct or indirect unless otherwise specified, and the present invention is not limited in this respect. Thus, coupling of entities may refer to direct or indirect coupling, and relationships between entities may be direct or indirect. Additionally, the various tasks and process steps described herein may be combined into a more comprehensive procedure or process having additional steps or functionality not specifically described herein.

[0011] The following definitions and abbreviations will be used for interpreting the claims and the specification. As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," "contains," or "containing," or any other variation thereof, are intended to include a non-exclusive inclusion. For example, a composition, mixture, process, method, article, or device that includes a list of elements is not necessarily limited to only those elements and may include other elements not expressly listed or inherent in such composition, mixture, process, method, article, or device.

[0012] Additionally, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations or designs. The terms "at least one" and "one or more" may be understood to include any integer number greater than one, i.e., one, two, three, four, etc. The term "a plurality" may be understood to include any integer number greater than two, i.e., two, three, four, five, etc. The term "connection" may include both an indirect and a direct connection.

[0013] The terms "about," "substantially," "approximately," and variations thereof are intended to include the degree of error associated with measurement of a particular quantity based on equipment available at the time of filing. For example, "about" can include a range of ±8%, or 5%, or 2% from a given value.

[0014] For the sake of brevity, prior art related to making and using aspects of the present invention may or may not be described in detail herein. In particular, various aspects of computing systems and particular computer programs for implementing various technical features described herein are well known. Accordingly, for the sake of brevity, many conventional implementation details are only briefly mentioned herein or omitted entirely, and details of well-known systems and / or processes are not provided.

[0015] Although this disclosure includes detailed descriptions of the invention with respect to cloud computing, it should be understood that implementation of the teachings recited herein is not limited to a cloud computing environment. Rather, embodiments of the invention can be implemented in conjunction with any other type of computing environment now known or later developed.

[0016] Cloud computing is a service delivery model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, network bandwidth, servers, processing, memory, storage, applications, virtual machines, and services) that can be rapidly provisioned and released with minimal administrative effort or interaction with the service provider. The cloud model can include at least five characteristics, at least three service models, and at least four deployment models.

[0017] The features are as follows:

[0018] On-demand self-service: Cloud consumers can unilaterally provision computing capacity, such as server time and network storage, as needed without the need for human interaction with the provider of the service.

[0019] Broad network access: Functionality is available over the network and accessed via standard mechanisms that facilitate use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs).

[0020] Resource Pooling: A provider's computing resources are pooled to serve multiple consumers using a multi-tenant model, and various physical and virtual resources are dynamically allocated and reallocated according to demand. Consumers generally have no control or knowledge of the exact location of the provided resources, but are said to be location-independent in that they may be able to identify a location at a higher level of abstraction (e.g., country, state, or data center).

[0021] Rapid Elasticity: Capabilities can be quickly and elastically provisioned, sometimes automatically, quickly scaled out, quickly released and quickly scaled in. To the consumer, the capabilities available for provisioning are often unlimited and can be purchased in any quantity at any time.

[0022] Measured Services: Cloud systems automatically control and optimize resource usage by using metering capabilities at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported, providing transparency to both providers and consumers of the services being used.

[0023] The service model is as follows:

[0024] Software as a Service (SaaS): The ability to offer consumers the ability to use a provider's applications running on a cloud infrastructure. The applications are accessible from a variety of client devices through a thin-client interface, such as a web browser (e.g., web-based email). The consumer does not manage or control the underlying cloud infrastructure, including the network, servers, operating systems, storage, or even individual application functions, with the possible exception of limited user-specific application configuration settings.

[0025] Platform as a Service (PaaS): The capability offered to a consumer to deploy consumer-created or acquired applications, created using programming languages and tools supported by the provider, onto a cloud infrastructure. The consumer does not manage or control the underlying cloud infrastructure, including networks, servers, operating systems, or storage, but does have control over the deployed applications and, in some cases, the application hosting environment configuration.

[0026] Infrastructure as a Service (IaaS): The capability offered to consumers to provision processing, storage, network, and other basic computing resources on which they can deploy and run any software, which may include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure, but does have control over the operating system, storage, deployed applications, and in some cases, limited control over the selection of network components (e.g., host firewalls).

[0027] The deployment models are as follows:

[0028] Private Cloud: Cloud infrastructure is operated exclusively for an organization. The cloud infrastructure may be managed by the organization or a third party and may reside on-premises or off-premises.

[0029] Community Cloud: Cloud infrastructure is shared by several organizations and supports a specific community with common concerns (e.g., mission, security requirements, policies, and compliance considerations). The cloud infrastructure may be managed by the organizations or a third party and may reside on-premises or off-premises.

[0030] Public Cloud: Cloud infrastructure is available to the general public or large industry groups and is owned by organizations that sell cloud services.

[0031] Hybrid Cloud: A cloud infrastructure is a blend of two or more clouds (private, community, or public) that remain unique entities but are brought together by standardized or proprietary technologies that enable data and application portability (e.g., cloud bursting for load balancing between clouds).

[0032] A cloud computing environment is service oriented with a focus on statelessness, low coupling, modularity, and semantic interoperability. At the heart of cloud computing is an infrastructure comprising a network of interconnected nodes.

[0033] Referring now to FIG. 1 , an exemplary cloud computing environment 50 is illustrated. As shown, the cloud computing environment 50 includes one or more cloud computing nodes 10, with which local computing devices used by cloud consumers, such as a personal digital assistant (PDA) or mobile phone 54A, a desktop computer 54B, a laptop computer 54C, or an automobile computer system 54N, or any combination thereof, may communicate. The nodes 10 may also communicate with each other. The nodes 10 may be physically or virtually grouped into one or more networks (not shown), such as a private cloud, community cloud, public cloud, or hybrid cloud, or any combination thereof, as described hereinabove. This allows the cloud computing environment 50 to provide infrastructure, platform, or software, or any combination thereof, as a service without the cloud consumer having to maintain resources on their local computing device. It is understood that the types of computing devices 54A-N shown in FIG. 1 are intended to be illustrative only, and that computing node 10 and cloud computing environment 50 can communicate with any type of computerized device (e.g., using a web browser) over any type of network or network-addressable connection or combination thereof.

[0034] Referring now to Figure 2, a set of functional abstraction layers provided by cloud computing environment 50 (Figure 1) is shown. It should be understood that the components, layers, and functions shown in Figure 2 are intended to be exemplary only, and that embodiments of the present invention are not limited thereto. As shown, the following layers and corresponding functions are provided:

[0035] The hardware and software layer 60 includes hardware and software components. Examples of hardware components include mainframes 61, RISC (Reduced Instruction Set Computer) architecture-based servers 62, servers 63, blade servers 64, storage devices 65, and networks and networking components 66. In some embodiments, software components include network application server software 67 and database software 68.

[0036] The virtualization layer 70 provides an abstraction layer from which the following examples of virtual entities are provided: virtual servers 71, virtual storage 72, virtual networks 73, including, for example, virtual private networks, virtual applications and operating systems 74, and virtual clients 75.

[0037] In one example, the management layer 80 may provide the following functions: Resource provisioning 81 provides dynamic procurement of computing and other resources used to execute tasks within the cloud computing environment. Metering and pricing 82 provides cost tracking as resources are utilized within the cloud computing environment and billing or invoicing for the consumption of these resources. In one example, these resources may include application software licenses. Security provides identity verification for cloud consumers and tasks and protection for data and other resources. User portal 83 provides access to the cloud computing environment for consumers and system administrators. Service level management 84 provides allocation and management of cloud computing resources so that required service levels are met. Service level agreement (SLA) planning and fulfillment 85 provides pre-provisioning and procurement of cloud computing resources where future requirements are predicted according to SLAs.

[0038] The workload tier 90 provides examples of functions for which a cloud computing environment may be utilized. Examples of workloads and functions that may be provided from this tier include mapping and navigation 91, software development and lifecycle management 92, virtual classroom instructional delivery 93, data analytics processing 94, transaction processing 95, and predictively selecting virtual reality content 96 to proactively adapt to later available bandwidth conditions.

[0039] Referring now to a more detailed description of aspects of the present invention, Figure 3 depicts a high-level block diagram illustrating an example of a computer-based system 300 useful for implementing one or more embodiments of the present invention. While one exemplary computer system 300 is depicted, computer system 300 includes a communications path 326 that connects computer system 300 to additional systems, which may include one or more wide area networks (WANs) or local area networks (LANs), or both, such as the Internet, one or more intranets, or one or more wireless communication networks, or a combination thereof. Computer system 300 and the additional systems communicate (e.g., transmit data between each other) via communications path 326.

[0040] Computer system 300 includes one or more processors, e.g., processor 302. Processor 302 is connected to a communications infrastructure 304 (e.g., a communications bus, crossover bar, or network). Computer system 300 may include a display interface 306 that transfers graphics, text, and other data from communications infrastructure 304 (or from a frame buffer, not shown) for display on a display unit 308. Computer system 300 further includes a main memory 310, preferably random access memory (RAM), and may further include a secondary memory 312. Secondary memory 312 may include, for example, a hard disk drive 314 and / or a removable storage drive 316, e.g., a floppy disk drive, magnetic tape drive, or optical disk drive. Removable storage drive 316 reads from and / or writes to a removable storage unit 318 in a manner well known to those skilled in the art. Removable storage unit 318 represents, for example, a floppy disk, compact disk, magnetic tape, or optical disk that is read by and written to by removable storage drive 316. As will be appreciated, removable storage unit 318 comprises a computer-readable medium having computer software and / or data stored thereon.

[0041] In some alternative embodiments of the present invention, secondary memory 312 may include other similar means for allowing computer programs or other instructions to be loaded into the computer system. Such means may include, for example, removable storage unit 320 and interface 322. Examples of such means may include program packages and package interfaces (e.g., those found in video game devices), removable memory chips (e.g., EPROM or PROM) and associated sockets, and other removable storage units 320 and interfaces 322 that allow software and data to be transferred from removable storage unit 320 to computer system 300.

[0042] Computer system 300 may further include a communications interface 324. Communications interface 324 allows software and data to be transferred between the computer system and external devices. Examples of communications interface 324 may include a modem, a network interface (e.g., an Ethernet card), a communications port, or a PCM-CIA slot and card. The software and data transferred via communications interface 324 are in the form of signals, which may be electronic, electromagnetic, optical, or other signals receivable by communications interface 324. These signals are provided to communications interface 324 via communications path (i.e., channel) 326. Communications path 326 carries signals and may be implemented using wire or cable, fiber optics, a telephone line, a cellular phone link, an RF link, or other communications channel, or a combination thereof.

[0043] In this disclosure, the terms “computer program medium,” “computer usable medium,” and “computer-readable medium” are used generally to refer to media such as main memory 310, secondary memory 312, removable storage drive 316, and a hard disk attached to hard disk drive 314. Computer programs (also called computer control logic) are stored in main memory 310, secondary memory 312, or both. Computer programs may also be received via communications interface 324. Such computer programs, when executed, enable the computer system to implement the features of the present disclosure discussed herein. Specifically, when executed, the computer programs enable processor 302 to implement the features of the computer system. Thus, such computer programs represent the controller of the computer system.

[0044] In general, holography is the process of recording diffracted light fields scattered from an object. The recorded diffracted light field from an object, also referred to herein as a holographic pattern, will be identical to a holographic pattern from the same object. However, if a small deformation or change is made to one of the objects, the relative phase of the two light fields will change, and interference can be observed by superimposing the two holographic patterns. This technique is referred to herein as holographic interferometry.

[0045] In exemplary embodiments, a method, system, and computer program or computer program product are provided for performing appearance quality assessment using holographic interferometry. In exemplary embodiments, appearance quality assessment of a test object is performed using holographic interferometry by comparing a holographic pattern of the test object with a holographic pattern of the reference object. The holographic patterns are superimposed to generate an interference pattern, and the interference pattern is analyzed to determine differences between the reference object and the test object.

[0046] Referring now to FIG. 4, a system 400 for capturing a holographic pattern of an object, according to one embodiment, is described below. The system 400 shown in FIG. 4 includes a light source 402 that emits a coherent light beam. The light source 402 can emit monochromatic or spread-spectrum light. The light beam impinges on a beam splitter 404, which splits the light beam into an illumination beam and a reference beam. The illumination beam is directed toward an object 408, and the reference beam is directed toward a mirror 406. The illumination beam impinges on the object and generates an object beam that is directed toward a recording device 410. The reference beam is also directed toward the recording device 410 by the mirror 406. In an exemplary embodiment, the recording device 410 is one of a photographic plate and a digital sensor array. As will be understood by those skilled in the art, system 400 illustrates one system for capturing a holographic pattern of an object, and other systems may be used to capture a holographic pattern of an object.

[0047] In an exemplary embodiment, once the holographic patterns of a reference object and a test object are acquired, the holographic pattern of the reference object is superimposed on the holographic pattern of the test object to generate an interference pattern. FIG. 5 shows various example interference patterns 502, 504, and 506 in accordance with one or more embodiments of the present invention. The first interference pattern 502 shows the superimposition of holographic patterns of two identical objects. The second interference pattern 504 shows the superimposition of holographic patterns of two objects with a large degree of difference. The third interference pattern 506 shows the superimposition of holographic patterns of two objects with a moderate degree of difference. In an exemplary embodiment, various techniques can be used to analyze the interference patterns and quantify the difference between the two objects used to generate the interference patterns. In one embodiment, the difference between the two objects is negatively correlated with the amount of white space present in the interference pattern. For example, an interference pattern with 100% white space represents the objects being identical, and as the amount of white space in the interference pattern decreases, the difference between the two objects increases.

[0048] Referring now to FIG. 6 , a flow diagram of a method 600 for performing appearance quality assessment using holographic interferometry is shown, according to one embodiment. Method 600 begins, at block 602, by acquiring a reference holographic pattern based on a reference object. In an exemplary embodiment, the reference holographic pattern is acquired by applying digital holography to the reference object. Next, as shown at block 604, method 600 includes acquiring a test holographic pattern based on a test object. In an exemplary embodiment, the test holographic pattern is acquired by applying digital holography to the test object.

[0049] Method 600 also includes generating an interference pattern by overlaying the test holographic pattern on the reference holographic pattern, as indicated at block 606. Next, method 600 includes determining differences between the reference object and the test object based on the interference pattern, as indicated at block 608. In one embodiment, determining differences between the reference object and the test object includes performing binomial detection of the presence of data in the interference pattern. In another embodiment, determining differences between the reference object and the test object includes analyzing the interference pattern and assigning a score to the interference pattern based on the analysis, where a score of zero indicates the absence of data in the interference pattern. In one embodiment, the score is determined as 100 minus the percentage of white space in the interference pattern. In another embodiment, the score is determined using a trained neural network.

[0050] In an exemplary embodiment, the method includes determining that the difference is less than an acceptable tolerance based on the score being less than a first value. In other words, the method determines that the test object is similar enough to the reference object to fall within an acceptable difference level based on the score being less than the first value. In an exemplary embodiment, the method includes determining that the difference is greater than an acceptable tolerance based on the score being greater than a second value. In other words, the method determines that the test object is too different from the reference object to fall within an acceptable difference level based on the score being greater than the second value. In an exemplary embodiment, if the score is greater than the first value and less than the second value, the method includes flagging the test object for further testing. In other words, the method determines that the test object is not sufficiently similar to the reference object to fall within an acceptable difference level, and not different enough to be disqualified for falling within an acceptable difference level. In an exemplary embodiment, the additional inspection may utilize more computationally intensive vision-based tools, such as Visual Inspector (VI) and Power AI Vision (PAIV) created by IBM (registered trademarks of IBM Corporation).

[0051] In an exemplary embodiment, an interference pattern produced by superimposing the test holographic pattern on the reference holographic pattern is analyzed using a neural network configured to assign the score to the interference pattern, the neural network being trained based on a plurality of interference patterns representing associated degrees of mismatch between the reference object and a plurality of control objects.

[0052] In an exemplary embodiment, the method for performing appearance quality assessment using holographic interferometry can be used to perform appearance quality assessment on any object, including any high precision objects, such as internal engine parts, semiconductor components, medical devices, etc.

[0053] In an exemplary embodiment, holographic interferometry is digitally employed by generating a digital holographic pattern from a reference object and overlaying diffracted light from a test object onto the digital holographic pattern. If the test object is identical to the reference object, no interference pattern is observed. If the test object has an acceptable defect tolerance relative to the reference object, the score assigned to the interference pattern will be less than a threshold. Similarly, if the test object does not have an acceptable defect tolerance relative to the reference object, the score assigned to the interference pattern will be greater than a threshold. In one embodiment, the mere presence or absence of an interference pattern is a simple, rapid, and inexpensive means of assessing the appearance similarity attribute between two objects (i.e., requiring less computational resources than existing AI vision-based tools). Thus, in one embodiment, a simple binary detection of the presence or absence of an interference pattern is used to determine the difference between the reference object and the test object.

[0054] Technical advantages include improved functionality of computer systems capable of performing appearance quality assessment using holographic interferometry, and in one embodiment, the computational resources required to perform appearance quality assessment are significantly reduced by using holographic interferometry compared to conventional artificial intelligence (AI) appearance inspection systems.

[0055] The present invention may be a system, method, or computer program product, or any combination thereof, which may include one or more computer-readable storage media having computer-readable program instructions for causing a processor to perform aspects of the present invention.

[0056] The computer-readable storage medium can be a tangible device capable of holding and storing instructions for use by an instruction execution device. The computer-readable storage medium can be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. A non-exhaustive list of more specific examples of computer-readable storage media includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as a punch card or a ridge structure in a groove in which instructions are recorded, or any suitable combination thereof. As used herein, a computer-readable storage medium should not be construed as a transitory signal per se, such as an electric wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse passing through a fiber optic cable), or an electrical signal transmitted over an electrical wire.

[0057] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to an individual computing device / processing device or to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, or a wireless network, or a combination thereof. The network may be comprised of copper transmission cables, fiber optic transmission cables, wireless transmissions, routers, firewalls, switches, gateway computers, or edge servers, or a combination thereof. A network adapter card or network interface in each computing device / processing device receives the computer-readable program instructions from the network and transmits the computer-readable program instructions to the individual computing device / processing device for storage in a computer-readable storage medium.

[0058] Computer-readable program instructions for carrying out operations of the present invention may be either assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, configuration data for an integrated circuit, or source or object code written in any combination of one or more programming languages, such as object-oriented programming languages (e.g., Smalltalk, C++, etc.), procedural programming languages (e.g., the "C" programming language or similar programming languages). The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, partially on the user's computer as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer via any type of network, such as a local area network (LAN) or a wide area network (WAN), or the connection may be to an external computer (e.g., over the Internet using an Internet Service Provider). In some embodiments, electronic circuits, such as programmable logic circuits, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), may execute computer-readable program instructions by utilizing state information of the computer-readable program instructions to personalize the electronic circuitry to perform aspects of the invention.

[0059] Aspects of the present invention are described herein with reference to flowchart illustrations or block diagrams, or combinations thereof, of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations or block diagrams, or combinations thereof, and combinations of blocks in the flowchart illustrations or block diagrams, or combinations thereof, can be implemented by computer-readable program instructions.

[0060] These computer-readable program instructions may be provided to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when the instructions are executed by the processor of the computer or other programmable data processing apparatus, means for implementing the functions / acts specified in one or more blocks of the flowchart illustrations and / or block diagrams are generated. The computer-readable program instructions may also be stored on a computer-readable storage medium capable of directing a computer, programmable data processing apparatus, or other device, or combination thereof, to function in a particular manner, such that the computer-readable storage medium on which the instructions are stored constitutes an article of manufacture containing instructions that implement aspects of the functions / acts specified in one or more blocks of the flowchart illustrations and / or block diagrams.

[0061] The computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device such that the instructions, which execute on the computer, other programmable data processing apparatus, or other device, implement the functions / operations identified in one or more blocks of the flowcharts or block diagrams, or combinations thereof, causing the computer, other programmable apparatus, or other device to perform a series of operational steps to generate a computer-implemented process.

[0062] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowcharts or block diagrams may represent a module, segment, or portion of instructions, which includes one or more executable instructions for implementing one or more specified logical functions. In some alternative implementations, the functions shown in the blocks may occur out of the order shown in the figures. For example, two blocks shown in succession may actually be accomplished as a single step performed simultaneously, substantially simultaneously, partially, or fully in a time-overlapping manner, depending on the functionality involved, or the blocks may be performed in the reverse order. It should also be noted that each block of the block diagrams or flowchart diagrams or combinations thereof, and combinations of multiple blocks in the block diagrams or flowchart diagrams or combinations thereof, may be implemented by a special-purpose hardware-based system that performs the specified functions or operations, or may execute a combination of special-purpose hardware and computer instructions.

[0063] The description of various embodiments of the present invention has been presented for purposes of illustration, but is not intended to be exhaustive or to be limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terms used in this specification have been selected to explain the principles of the embodiments, practical applications or technical improvements to commercially available technology, or to enable those skilled in the art to understand the embodiments disclosed herein. [Explanation of symbols]

[0064] 400 System 402 Light source 404 Beam Splitter 406 Mirror 408 Object 410 Recording Devices

Claims

1. 1. A method for performing appearance quality assessment using holographic interferometry, comprising: a processor obtaining a reference holographic pattern based on the reference object; the processor obtaining a test holographic pattern based on a test object; the processor generating a difference pattern representing differences between the test holographic pattern and the reference holographic pattern by overlaying the test holographic pattern on the reference holographic pattern; and the processor determining a difference between the reference object and the test object based on the difference pattern. Including, determining the difference between the reference object and the test object includes analyzing the difference pattern and assigning a score to the difference pattern based on the analysis; the difference pattern is analyzed using a neural network configured to assign the score to the difference pattern, wherein the neural network is trained based on a plurality of difference patterns representing associated degrees of disparity between the reference object and a plurality of control objects. The method.

2. The method of claim 1 , wherein the reference holographic pattern is obtained by digital holographic interferometry of the reference object.

3. The method of claim 1 , wherein the test holographic pattern is obtained by applying digital holography to the test object.

4. 4. The method of claim 1, wherein determining the difference between the reference object and the test object comprises performing a binary detection of the presence of data in the difference pattern.

5. A method according to any one of claims 1 to 4, wherein a score of zero indicates the absence of data in the difference pattern.

6. 6. The method of claim 5, further comprising determining that the difference is less than an acceptable difference based on the score being less than a first value, and determining that the difference is greater than an acceptable difference based on the score being greater than a second value.

7. The method of claim 6 , further comprising flagging the test object for further inspection based on the score being greater than the first value and less than the second value.

8. 1. A system for performing appearance quality assessment using holographic interferometry, comprising: a memory having computer readable instructions; a processor for executing the computer-readable instructions; wherein the computer readable instructions include: obtaining a reference holographic pattern based on the reference object; obtaining a test holographic pattern based on the test object; generating a difference pattern representing differences between the test holographic pattern and the reference holographic pattern by superimposing the test holographic pattern on the reference holographic pattern; and determining a difference between the reference object and the test object based on the difference pattern; Contains instructions for determining the difference between the reference object and the test object includes analyzing the difference pattern and assigning a score to the difference pattern based on the analysis; the difference pattern is analyzed using a neural network configured to assign the score to the difference pattern, wherein the neural network is trained based on a plurality of difference patterns representing associated degrees of disparity between the reference object and a plurality of control objects. The system.

9. The system of claim 8 , wherein the reference holographic pattern is obtained by digital holographic interferometry of the reference object.

10. The system of claim 8 , wherein the test holographic pattern is obtained by applying digital holography to the test object.

11. 11. The system of claim 8, wherein determining the difference between the reference object and the test object comprises performing a binary detection of the presence of data in the difference pattern.

12. A system described in any one of claims 8 to 11, wherein a score of zero indicates the absence of data in the difference pattern.

13. 13. The system of claim 12, wherein the computer-readable instructions further comprise instructions for determining that the difference is less than an acceptable difference based on the score being less than a first value, and determining that the difference is greater than an acceptable difference based on the score being greater than a second value.

14. 14. The system of claim 13, wherein the computer-readable instructions further comprise instructions for flagging the test object for further inspection based on the score being greater than the first value and less than the second value.

15. 1. A computer program for performing appearance quality assessment using holographic interferometry, comprising: obtaining a reference holographic pattern based on the reference object; obtaining a test holographic pattern based on the test object; generating a difference pattern representing differences between the test holographic pattern and the reference holographic pattern by superimposing the test holographic pattern on the reference holographic pattern; and determining a difference between the reference object and the test object based on the difference pattern; causing a computer processor to execute determining the difference between the reference object and the test object includes analyzing the difference pattern and assigning a score to the difference pattern based on the analysis; the difference pattern is analyzed using a neural network configured to assign the score to the difference pattern, wherein the neural network is trained based on a plurality of difference patterns representing associated degrees of disparity between the reference object and a plurality of control objects. The computer program.

16. 16. The computer program of claim 15, wherein the reference holographic pattern is obtained by digital holographic interferometry of the reference object.

17. 16. The computer program product of claim 15, wherein the test holographic pattern is obtained by applying digital holography to the test object.

18. 18. The computer program product of claim 15, wherein determining the difference between the reference object and the test object comprises performing a binomial detection of the presence of data in the difference pattern.

19. A computer program as claimed in any one of claims 15 to 18, wherein a score of zero indicates the absence of data in the difference pattern.

20. The method further comprising determining that the difference is less than an acceptable difference based on the score being less than a first value, and determining that the difference is greater than an acceptable difference based on the score being greater than a second value; while flagging the test object for further testing based on the score being greater than the first value and less than the second value.

20. The computer program product of claim 19.

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