Two important standards are briefly introduced in this section, hosted by the European machine vision associate (EMVA), a non-profit organisation founded in 2003. The EMVA aims to connect organisations in machine vision, computer vision, embedded vision and imaging technologies, which includes manufacturers, system and machine builders, integrators, distributors, consultancies, research organisations and academia (EMVA 2022).
The reason for introducing these standards is that a standard might be valuable for comparing different sensors and it may enable a more versatile programming interface than a common programming library.
The first standard is EMVA 1288, which can be used for comparing sensors; the second standard is GenICam, which provides a generic programming interface for sensors and other devices.
When comes to authors’ hands-on experience, the GenICam standard is the foundation of the Python library Camazing (Jääskeläinen et al. 2019a), which is used with VTTs HS imagers, which are mentioned also in my posts. Camazing was developed at the Spectral Imaging Laboratory at the University of Jyväskylä (JYU 2022) with an MIT license.
EMVA 1288
Sensor selection is the first phase, and one of the most important ones in the image-capturing process. Manufacturers offer a large selection of different sensors, which vary in their price. Some of the properties introduced in the Post 2.2 are definably dependent on the requirements of the target; such as the resolution, the choice between monochromatic or colour sensor, the shutter type and the camera interface. The challenge lies in the measurable features; such as the sensor’s sensitivity, temporal noise and spectral response.
EMVA 1288 is a standard for the specification and measurement of machine vision sensors and cameras (EMVA 2022). Its main purpose is to create transparency by defining reliable and exact measurement procedures and data presentation guidelines to make comparing cameras and image sensors easier.
Manufacturers that do not hold EMVA licences might measure and present the sensor performance and feature measurements differently and may even leave some important details to the buyers to test, which might be expensive and difficult.
Manufacturers that adhere to the EMVA 1288 standard measure the sensors and cameras according to the standard’s exact measurement procedures, making the presented data sheets of different sensors and sensor manufacturers comparable. The “EMVA standard 1288 compliant” logo ensures that products are licensed, measured and presented transparently and reliably.
The complete list of measurement groups and their mandatorily can be found in the standard specification (EMVA 2016). The standard’s documentation includes mathematical formulas, descriptions of the measurement setups and guidelines for presenting the results in a consistent format. The current release cited in this Post is 3.1.
GenICam standard
Generic Interface for Cameras (GenICamTM) provides a generic programming interface for various sensors, cameras and other devices, regardless of the interface technology (GigE Vision, USB3 Vision, CoaXPress, Camera Link HS, Camera Link, etc.) they use or what the features they implement.
The GenICam standard comprises five modules, which are introduced above in Table 4. The role of GenApi is to define the mechanism used to provide the generic application defining interface (API) via a self-describing eXtensible Markup Language (XML) file in the device. The XML file format is defined in Schema, which is a part of GenApi. Underneath GenApi is the standard features naming convention (SFNC), which standardises the name, type, meaning and use of device features, resulting in standard functionalities between manufacturers. The features are typically introduced in a tree view, being controllable via an application. The related standard for the consistent naming of pixel formats is the pixel format naming convention (PFNC).
GenTL is the standard for the transport layer programming interface. As a low-level API, it provides standard device interfaces and allows one to enumerate devices, access device registers, stream data and deliver asynchronous events. Data Container (GenDC) module allows devices to send any form of data (e.g. 1D, 2D, 3D, multi-spectral, metadata) in a Transport Layer Protocol (TLP) independent format and permits to share of a common data container format for all the TLP standards. The control protocol (GenCP) is a low-level standard to define the packet format for device control and can be used as a control protocol for each new standard.
The main purpose and benefit of GenICam are to provide an API, which is identical regardless of interface technology used in standardised devices (GenICam 2022).
Found something useful? Wish to cite? This post is based on my dissertation. For citations and more information, click here to see the scientific version of it.
References
GenICam 2022. The European machine vision association, GenICam standard, version 2.1.1. https://www.emva.org/standards-technology/genicam/ introduction-new/
EMVA 2022. The European machine vision association, home page. https: /www.emva.org/. (Organisation behind sensor and camera standards. Accessed on 8.4.2022).
Jääskeläinen, S., Eskelinen, M., Annala, L. & Raita-Hakola, A.-M. 2019a. Camazing Python library. https://pypi.org/project/camazing/. (Machine vision library for GenICam-compliant cameras. Developed at the University of Jäskylä, Spectral Imaging Laboratory. Released under MIT-licence. Accessed on 9.4.2022).