1. EMVA1288 Standard
Developed by the European Machine Vision Association (EMVA), EMVA1288 provides the vision industry with test standards for key performance parameters of cameras and image sensors, and is accepted by industry organizations such as CMVU of China, AIA of the U.S.A., JIIA of Japan, and VDMA of Germany, and is the international and domestic common test standard for cameras and image sensors.
2. Purpose of The Standard
2.1 Provide a unified platform for manufacturers to demonstrate the performance of their products and a set of precise measurement, calculation and presentation methods for testing and evaluating camera performance.
2.2 Provide users with a quantitative and transparent tool for evaluating camera performance.
3.Interpretation of Key Parameters
| Parameters | Interpretation | Measure Unit | Importance |
| Quantum efficiency | The ratio of the number of electrons generated at the sensor and collected by the incident photon to the number of incident photons under a specified wavelength of illumination | % | Higher value means higher sensitivity in detecting light, which is more favorable in low light and low light application environments. Note: No sensor is 100% efficient. |
| Dark currents | Background current generated by the image sensor during normal operation in the absence of light and at a specified ambient temperature | e-/s | Higher values mean unwanted noise in the image, affecting the image quality. |
| Dynamic range | The ratio between the maximum signal and the minimum signal that an image sensor can capture | dB | The higher the value, the higher the gray scale detail level of the image is obtained. Represents the camera's ability to detect rapidly changing lighting conditions |
| Linearity | Maximum deviation between sensor calibration curve and fitted straight line ( Ymax) vs. percentage of full scale output (Y) | % | A measure of the static characteristics of the sensor, the lower the value, the better the linearity characteristics, the more accurate the measurement results |
| Dark noise | Inherent noise in sensor output in complete darkness | e- | The lower the value, the more detail and texture is preserved, especially in low light conditions. |
| Saturation capacity | Maximum charge that can be linearly accommodated in a single pixel | e- | Saturation capacity indicates the maximum number of electrons that can be stored in a single pixel; the higher the value, the greater the potential dynamic range; usually saturation capacity is combined with dark noise and quantum efficiency to obtain dynamic range and signal-to-noise ratio results |
| Absolute sensitivity threshold | Lowest level of light intensity that can be detected by the sensor | y | The lower the value, the better the camera will be able to identify useful imaging data from the image noise |
| Signal-to-noise ratio | The ratio between the strength of the output signal of an image sensor and the intensity of the noise it produces | dB | The higher the value, the higher the contrast and sharpness of the obtained image relative to the noise in the image. For example, at 1 dB, it is difficult to identify the noise in the subject and image |
4. Application of the standard
The standard has been popularized and applied by international famous camera manufacturers such as Basler and Baumer, and sensor manufacturers such as Sony and onsemi. In the domestic high-speed vision industry, Revealer takes the lead in practicing EMVA1288 standard, which is used in the imaging performance evaluation of high-speed cameras and scientific cameras under the brand.
5. Test Improvement Analysis
In order to be more suitable for users of high-speed cameras and scientific cameras, such as detection in low-light environment, the performance parameter test is often not limited to the minimum gain, Revealer realizes the test of optoelectronic performance parameters of the camera under different gains, which provides a more comprehensive and accurate assessment and facilitates the users to accurately understand the performance of the camera.
