Image sensors are at the heart of embedded vision applications, as they are responsible for capturing the visual data that forms the basis of image processing and computer vision algorithms. They capture the optical image of a scene and convert it into an electrical signal that can be processed by the system’s image processing algorithms.
Of course, the image sensor’s performance is critical for the overall performance of the embedded vision system. Factors like resolution, frame rate, and dynamic range can affect the quality of the captured images and the accuracy of the image processing algorithms.
Several types of image sensors are available on the market, including EMCCD, sCMOS, CMOS, and CCD. In this blog, we will compare these four types of image sensors and help you determine which is best for your application.
EMCCD vs. SCMOS vs. CMOS vs. CCD image sensors
The quality and capabilities of the image sensor directly impact the accuracy and effectiveness of the computer vision algorithms used in embedded vision applications. So, let’s look at the most popular image sensors in the market, along with their advantages and disadvantages,
EMCCD Image Sensors
EMCCD (Electron Multiplying CCD) sensors are a specialized type of CCD sensor for low-light imaging applications. They use an amplification process that can increase the sensor’s sensitivity and reduce the noise in the image. This amplification process is achieved by applying a high voltage to the sensor, which causes electrons to multiply as they move through the sensor.
Advantages of EMCCD image sensors:
- High sensitivity: EMCCD sensors have a high level of sensitivity, which makes them ideal for low-light imaging applications. They can detect extremely weak signals that other sensors may not.
- Low noise: EMCCD sensors have a low noise level, powering applications that require high signal-to-noise ratios, resulting in higher image quality.
- High frame rates: EMCCD sensors can achieve high frame rates for applications that require high-speed imaging to capture multiple frames per second.
- High dynamic range: EMCCD sensors have a high dynamic range, which means they can capture a scene’s bright and dark regions without losing detail.
Disadvantages of EMCCD image sensors:
- High cost: EMCCD sensors are more expensive than other types of image sensors.
- Comparatively limited dynamic range: While EMCCD sensors have a high dynamic range – it is still limited compared to sCMOS or CCD sensors.
- Limited lifetime: EMCCD sensors have a limited lifetime due to the amplification process used in the sensor
- Limited resolution: EMCCD sensors have a limited resolution compared to other sensors, such as CMOS or sCMOS.
sCMOS Image Sensors
sCMOS (Scientific CMOS) sensors are a newer type of CMOS sensor designed for scientific and industrial applications. They are a hybrid between CCD and CMOS sensors and offer a good balance between sensitivity, speed, and resolution. sCMOS sensors leverage an architecture that allows them to achieve high levels of sensitivity and low noise while still maintaining high frame rates and a large field of view.
Advantages of sCMOS image sensors:
- High sensitivity: sCMOS sensors offer high sensitivity, making them suitable for low-light imaging applications.
- High frame rates: sCMOS sensors offer fast readout speeds, which allows them to capture high-speed imaging with high frame rates for real-time imaging and analysis.
- High dynamic range: sCMOS sensors have a high dynamic range, so they can capture bright and dark regions of a scene without losing detail.
- Large field of view: sCMOS sensors offer a large field of view, which allows for wide-angle imaging and the ability to capture large objects or scenes.
Disadvantages of sCMOS image sensors:
- High cost: sCMOS sensors are more expensive than traditional CMOS sensors.
- Limited lifetime: sCMOS sensors have a limited lifetime due to the high readout speeds and high temperatures generated during operation.
- Limited resolution: sCMOS sensors have a limited resolution compared to other types of sensors like CCD.
- Sensitivity to cosmic rays: sCMOS sensors are sensitive to cosmic rays, which can result in image artifacts or data loss.
CMOS Image Sensors
CMOS (Complementary Metal-Oxide-Semiconductor) sensors are the most common type of image sensor used in consumer electronics. They offer a low-cost and low-power alternative to CCD sensors. CMOS sensors use a different technology than CCD sensors, which allows them to achieve higher frame rates and lower power consumption.
Advantages of CMOS image sensors:
- Low power consumption: CMOS sensors consume less power than other types of sensors, which can result in longer battery life.
- Low cost: CMOS sensors are relatively inexpensive compared to CCD sensors.
- High frame rates: CMOS sensors can capture multiple frames per second, allowing for real-time imaging and analysis.
- High resolution: CMOS sensors offer high resolution, making them suitable for applications that require high-quality imaging with fine details.
- Large field of view: CMOS sensors offer a large field of view to enable wide-angle imaging and provide the ability to capture large objects or scenes.
Disadvantages of CMOS image sensors:
- Lower sensitivity: CMOS sensors have lower sensitivity compared to CCD or EMCCD sensors.
- Lower dynamic range: CMOS sensors have a lower dynamic range compared to sCMOS or EMCCD sensors.
- Higher noise: CMOS sensors have higher levels of noise compared to EMCCD or sCMOS sensors.
CCD Image Sensors
CCD (Charge-Coupled Device) sensors were once the most common type of image sensor used in digital cameras and other imaging applications. They offer high sensitivity and low noise, making them ideal for scientific and industrial applications. CCD sensors use a unique architecture that allows them to capture high-quality images with high levels of detail.
Advantages of CCD image sensors:
- High sensitivity: CCD sensors are known for their high sensitivity to light, making them ideal for capturing images in dimly lit environments without introducing a lot of noise.
- High dynamic range: CCD sensors have a high dynamic range to capture images with a wide range of brightness levels.
- Low noise: CCD sensors have low levels of noise – making them ideal for scientific and industrial applications that require accurate measurements.
Disadvantages of CCD Image Sensors:
- Slow readout speeds: CCD sensors have slower readout speeds than CMOS or sCMOS sensors.
- High power consumption: CCD sensors require more power to operate than sensors like CMOS or sCMOS.
- High cost: CCD sensors are more expensive compared to CMOS or sCMOS sensors.
- Limited resolution: CCD sensors have a limited resolution compared to other types of sensors, such as sCMOS.
e-con Systems can help select the perfect image sensor for your application
At the end of the day, image sensors play a crucial role in embedded vision applications. However, selecting the right one for your application may be a rocky road without the help of an expert. e-con Systems has a proven track record of helping clients choose their best-fit image sensor for close to two decades. Our team of engineers has vast experience in developing camera solutions for a variety of industries, including automotive, medical, industrial, and smart cities. We are extremely familiar with the various types of image sensors available and can provide valuable insights into each type of sensor.
e-con Systems also offers customization services, allowing granular customization of our camera solutions to meet your specific requirements. Hence, we can help modify the camera modules to include different lenses, filters, and other accessories to optimize the camera’s performance for your application.
So, if you are interested in integrating embedded cameras with the right image sensor into your products, kindly write to firstname.lastname@example.org. You can also visit our Camera Selector to get a complete view of e-con Systems’ camera portfolio.
Prabu is the Chief Technology Officer and Head of Camera Products at e-con Systems, and comes with a rich experience of more than 15 years in the embedded vision space. He brings to the table a deep knowledge in USB cameras, embedded vision cameras, vision algorithms and FPGAs. He has built 50+ camera solutions spanning various domains such as medical, industrial, agriculture, retail, biometrics, and more. He also comes with expertise in device driver development and BSP development. Currently, Prabu’s focus is to build smart camera solutions that power new age AI based applications.