Optical Imaging Workflow

Introduction

Optical imaging systems are ubiquitous in our daily lives. Whether it's smartphones and consumer electronics, security surveillance, medical imaging, autonomous and assisted driving, industrial inspection automation, drones, or virtual reality, optical imaging technology is everywhere. This article provides a brief overview of the components of an optical imaging system to help readers better understand the basic principles behind imaging technology.

Core Components

Lens (LENS)

Function: The lens focuses light and directs it to the image sensor. The quality of the lens directly affects the sharpness and color accuracy of the image.

Parameters: Common parameters include focal length, aperture, and field of view (FOV). The focal length determines the viewing angle, while the aperture affects light intake and depth of field.

Image Sensor (CMOS/CCD)

Function: The image sensor converts light signals into electrical signals. CMOS (Complementary Metal-Oxide-Semiconductor) and CCD (Charge-Coupled Device) are the two main types of image sensors.

Parameters: Key parameters include resolution, pixel size, and dynamic range. Resolution determines image detail, pixel size affects sensitivity, and dynamic range measures the sensor's ability to handle contrast between light and dark.

Image Signal Processor (SoC chip with ISP module)

Function: The ISP processes and optimizes the raw image data output by the sensor to produce high-quality images.

Parameters: Key ISP functions include:

Optical Black Correction (OB)

Lens Shading Correction (LSC)

Auto Exposure (AE)

Auto White Balance (AWB)

Auto Focus (AF)

Bad Pixel Correction (BPC)

RAW Denoising (ABF)

Demosaicing

Color Correction (CC)

Global Tone Mapping (GTM)

Local Tone Mapping (LTM)

Gamma Correction

Color Space Conversion (CV)

Wavelet Noise Reduction (WNR)

Adaptive Sharpening (ASF)

Image Storage and Display (LCD and TP)

Function: The processed image can be stored on storage media (such as an SD card) or viewed in real-time via a display.

Format: Images are typically stored in JPEG or MP4 format, and displays may include built-in LCDs or external monitors.

Basic Principles

Light enters the lens: Light passes through the lens, which focuses the rays to form a sharp image on the sensor.

Light is converted into electrical signals: The light strikes the image sensor, which converts it into an electrical signal.

Image data is processed: The signal is sent to the Image Signal Processor (ISP), which performs a series of processes including 3A control and correction via ISP modules.

Image is stored or displayed: The processed image data can then be saved to storage media or displayed on a screen in real-time for user viewing and adjustment.

Conclusion

An optical imaging system transforms light into visual images through the processes of propagation, collection, conversion, and processing. Understanding its basic principles and components helps us apply and develop imaging systems more effectively, supporting applications across a wide range of industries. We hope this article provides a clearer understanding of the fundamentals of optical imaging systems.