Optimizing Embedded Vision: The Impact of CMOS Camera Sensor Sizes

I. Introduction

Innovation is a key factor for the economic growth in this age of advanced information and communication technologies. Therefore adoption of innovative technologies is of utmost importance for businesses to remain ahead of their competition. One such technology is embedded vision which plays a crucial role in different industries including defense, healthcare, manufacturing, surveillance, and autonomous vehicles. All embedded vision systems rely on image sensors for gathering visual data from their environment. Hence, the selection of appropriate image sensor is of great importance for any embedded vision application. In this article we will explore the significance of CMOS image sensor sizes in embedded vision applications and their impact on image quality, resolution, processing speed, and power consumption.

2: The crucial significance of camera sensor sizes

2.1: Why selecting the right sensor size is pivotal in embedded vision

The entire design and performance of an embedded vision system heavily relies on the selection of right image sensor size. Some of the key factors that depend on the image sensor size include:

1. Image quality
2. Field of View
3. Form factor
4. Power consumption
5. Processing speed
6. Cost

Considering the above listed factors, it is evident that the selection of right camera sensor size is crucial for the design of an embedded vision system.

2.2: How sensor size influences image quality, processing speed, and power consumption

Size of CMOS image sensor has a significant impact on image quality and camera performance. Larger image sensors offer better light sensitivity as they are able to capture more light. This leads to superior low-light performance and reduced image noise. Moreover, larger CMOS image sensors offer better dynamic range allowing them to capture a broad range brightness levels. Due to limited dynamic range, smaller image sensors have the problem of over and under exposed areas in the image. Another advantage of larger CMOS image sensors is that they offer better resolution due to larger number of pixels. Hence, larger sensors provide better quality images with high levels of clarity and sharpness.

Another important consideration in the design of embedded vision systems is processing speed. Lagging and slower camera systems can pose serious issues in real-time embedded applications which demand very low latency levels. Larger CMOS image sensors generate higher amounts of image data. Hence, more power CPUs and GPUs are required for processing, storage, and transmission of raw image data. Smaller CMOS image sensors offer better processing speeds but at the expense of inferior image quality.

The power consumption of a CPU or GPU is directly related to data processing speed. Larger CMOS sensors generate more data hence higher processing speed is required which leads to higher power consumption. Additionally, larger camera sensors themselves require more power to operate. In some cases, cooling mechanisms might be required to avoid excessive heat and potential burnout.

2.3: How the choice of sensor size directly impacts the success of embedded vision projects

As discussed earlier, sensor size is crucial for the success of any embedded vision project. Sensor size directly impacts the key design factors of an embedded vision system including field of view, resolution, light sensitivity, power consumption, cost, and compatibility. Hence, the success of any embedded vision or imaging system largely relies on the size and performance of its image sensor.

3: Types of camera sensor sizes

3.1: Overview of commonly used CMOS sensor sizes

The image sensor size is also referred to as optical format. The equation describing the optical format of an image sensor is:

Optical format = (3/2) x Diagonal of sensor

Typical image sensor sizes or optical formats for CMOS sensors are as following:

• 1/2’’
• 1/2.3’’
• 1/2.5’’
• 1/3’’
• 1/4’’
• 2/3’’
• 35 mm

1/2” Sensor:

This CMOS image sensor size is commonly used in consumer grade digital cameras webcams, and smart-phones. This compact sensor size offers a good balance between small form factor and image quality.

1/2.3” Sensor:

This CMOS image sensor size is slightly smaller than 1/2’’. This sensor is also widely used in digital cameras, action cameras, and webcams. Like 1/2’’ camera sensor, 1/2.3’’ CMOS image sensor also offer good image quality with a small form factor.

1/2.5” Sensor:

1/2.5’’ CMOS image sensor is even smaller than 1/2.3’’ sensor. These sensors are mostly used in applications required small form factor such as smart-phones, camcorders, and webcams.

1/3” Sensor:

1/3’’ CMOS image sensors are mostly employed in industrial and surveillance applications. The cameras offer compactness and cost-efficiency at the expense of image quality.

1/4” Sensor:

1/4’’ CMOS image sensors have an even smaller form factor as compared to the 1/3’’ sensors. These sensors are used in applications where image quality can be compromised for compactness. These sensors find their application in IoT devices and surveillance cameras.

2/3” Sensor:

2/3’’ is one of the larger CMOS image sensor sizes. These sensors offer better image quality especially in low-light conditions. These CMOS image sensor are commonly found in broadcast cameras, machine vision, and industrial inspection applications.

35 mm (Full-Frame) Sensor:

This is the largest CMOS image sensor size available. The full-frame CMOS image sensor offers exceptional image quality and low-light sensitivity. These image sensors are a de-facto standard in filmmaking, slow motion videography, and professional photography.

3.2: Advantages and limitations of each CMOS sensor size

1/2’’ image sensor
Advantages:

• Small form factor
• Good image quality

Disadvantages

• Limited low-light performance

1/2.3’’ image sensor
Advantages

• Small form factor
• Good image quality

Disadvantages

• Limited low-light performance

1/2.5’’ image sensor
Advantages

• Small form factor suitable for smartphones and webcams

Disadvantages

• Compactness comes at the cost of image quality

1/3’’ image sensor
Advantages

• Better image quality
• Good low light performance

Disadvantages

• Lower image quality compared to larger sensors

2/3’’ image sensor
Advantages

• Small form factor
• Good image quality

Disadvantages

• Unsuitable for compact sized applications

35mm image sensor
Advantages

• Exceptional image quality
• Excellent low light performance

Disadvantages

• High cost
• Large size

3.3: Specific embedded vision applications for each CMOS sensor size

1/2” Sensor:

• Surveillance systems
• Entry-level drones
• Low-cost webcams

1/2.3” Sensor:

• Outdoor action cameras
• Compact drones with image stabilization
• High-quality webcams for streaming

1/2.5” Sensor:

• Smartphones
• Camcorders
• Compact surveillance cameras

1/3” Sensor:

• Industrial inspection systems for quality control.
• Entry-level surveillance cameras in commercial settings.
• Traffic cameras for monitoring intersections.

2/3” Sensor:

• Advanced industrial inspection systems
• Machine vision systems for manufacturing and robotics
• Broadcast cameras

35 mm (Full-Frame) Sensor:

• High-end professional photography
• Medical imaging systems
• Advanced robotics and autonomous vehicles

4: Sensor size comparison

The comparison table for the different CMOS image sensor sizes is as following:

5: Conclusion

In conclusion, the selection of the right CMOS image sensor size is crucial for the success of embedded vision applications. CMOS image sensor sizes directly impacts various key factors and performance of the imaging system including image quality, resolution, low-light performance, dynamic range, and form factor. Larger CMOS sensors offer superior image quality and low-light performance but come with larger size and high power consumption. Contrarily, smaller CMOS sensors prioritize form factor and energy efficiency but often compromise on image quality. This article serves as a guideline for embedded vision system designers and OEMs for the selection of appropriate CMOS image sensor size for their embedded vision applications.