In this note, we are going to know about the Functional Block Diagram of Digital Camera. Welcome to Poly Notes Hub, a leading destination for engineering notes for diploma and degree engineering students.
Author Name: Arun Paul.
What is Digital Camera in Embedded System?
A digital camera is an electrical device that takes and saves digital photos and videos. Unlike traditional film cameras, digital cameras employ an image sensor (such as a CCD or CMOS sensor) to convert light into electrical signals, which are subsequently processed and saved as digital files (e.g., JPEG, PNG, RAW). Digital cameras are commonly utilized in smartphones, professional photography, surveillance systems, and multimedia applications due to their fast image preview, easy editing, and quick sharing capabilities.
Working of Digital Camera with Block Diagram
A digital camera captures light from a scene using its lens system, which focuses the light onto an image sensor. This image sensor, usually a CCD or CMOS chip, is protected by a Color Filter Array (CFA), which divides incoming light into red, green, and blue components. The sensor turns filtered light into electrical impulses based on each pixel’s brightness. These analog signals are subsequently amplified using Automatic Gain Control (AGC), which ensures consistent brightness, particularly in low-light circumstances. Following amplification, the signals are transformed to digital form via an Analog-to-Digital Converter (ADC).
The camera then uses automatic exposure and autofocus functions to ensure that the captured image is well-lit and cleanly focused. To obtain a full-color image from raw digital data, which originally has incomplete color information due to the CFA, a procedure known as demosaicing is used. This image is further enhanced with techniques such as white balance modification, noise reduction, sharpening, and color correction. After processing, the image is saved in the camera’s internal memory or on an external memory card in JPEG, PNG, or RAW formats. Throughout the process, the control and interface unit handles camera settings, user inputs, and display functions to ensure seamless operation and user interaction.
Simple Block Diagram of Digital Camera in Embedded System
Here is the functional block diagram of digital camera with explanation –
- Lenses System: The lens system is the primary component of a digital camera. It collects and concentrates light from the scene onto the picture sensor. The camera’s clarity, focus, and zoom capabilities are determined on the quality and kind of lens used. Advanced lenses may also have optical stabilization.
- Color Filter Array (CFA): The Color Filter Array (CFA) is positioned above the image sensor and is used to acquire color data. Because image sensors are fundamentally monochrome, the CFA converts light into red, green, and blue components (often in a Bayer pattern), allowing the sensor to generate color images.
- Image Sensor: The image sensor (such as CMOS or CCD) turns the focused light into electrical impulses. It is the heart of the digital camera, collecting the intensity of light at each pixel location and generating raw image data.
- Automatic Gain Control (AGC): AGC regulates the signal gain from the image sensor to guarantee that the brightness is consistent. It boosts the signal in low-light conditions to brighten the image while keeping noise levels under control.
- Analog to Digital Converter (ADC): The ADC converts the image sensor’s analog electrical impulses into digital data that can be processed by the camera’s internal processors. This step is necessary for subsequent digital image processing.
- Auto Exposure: This block automatically adjusts the exposure settings, including shutter speed and aperture, in response to the scene’s lighting conditions. The goal is to guarantee that the acquired image is not too dark or too bright.
- Auto Focus: The Auto Focus feature ensures that the image’s topic is sharp and clear. It analyzes picture data and operates the lens system to ensure that the subject is properly focused, typically utilizing contrast or phase detection methods.
- Demosaicing: Demosaicing is the process of recreating a full-color image from incomplete color samples generated by the CFA. It interpolates missing color values at each pixel to create a complete RGB image.
- Image Processing: This block modifies the raw image with a variety of methods, including white balance modification, noise reduction, contrast enhancement, sharpening, and color correction. It prepares an image for display or storage.
- Control and Interface: This unit controls user inputs (buttons, touchscreen), camera settings, file management, and connectivity with external devices. It serves as the link between the user and the camera’s internal functions.
- Storage: The final processed image is saved in a digital format (such as JPEG or RAW) on internal memory or external memory cards (such as an SD card). The storage block ensures that data is written effectively and may be retrieved for later use.