# 3. Object Detection Distances

Accurate object detection distances are fundamental to the effectiveness of the **AlphaX XVision Video Analytics Platform**. This section delves into the capabilities of standard HD cameras and 4K CCTV cameras, providing detailed insights into their detection ranges, recognition capabilities, and the factors influencing their performance. Understanding these parameters helps in selecting the appropriate camera technology and optimising installation for reliable vehicle monitoring.

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#### **Summary of Key Points**

* **Standard HD Cameras:**
  * Effective up to **25 meters**; ideal for close-range monitoring.
* **4K Cameras:**
  * Effective up to **40 meters**; suitable for long-range applications.
* **Influencing Factors:**
  * **Resolution, lens quality, sensor sensitivity**, and **environmental conditions** impact detection distances.
* **Recommendations:**
  * **Select cameras** based on specific surveillance requirements.
  * **Optimise settings** and perform thorough testing to ensure reliability.

<figure><img src="https://2528410345-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FB6Ja4QlJv7qMfQlUtujK%2Fuploads%2FfFWYXj90qPcQzlQlM9sE%2Fdetection%20distance.png?alt=media&#x26;token=284e69c3-32b4-4031-b86e-9d06a906d820" alt=""><figcaption><p>Typical detection distance for 4K and HD resolutions. Note actual results may be influenced by other factors.</p></figcaption></figure>

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### **Standard HD Camera (1080p)**

* **Effective Detection Distance:** Up to **25 meters** (approximately **82 feet**).
* **Recognition Capabilities:**
  * **Vehicle Detection:** Reliable within the entire effective range.
  * **Vehicle Classification:** Accurate identification of vehicle types (e.g., car, truck, bus) within **15 meters** (approximately **49 feet**).
  * **License Plate Recognition:** Generally effective within **10 meters** (approximately **33 feet**), depending on lighting and camera quality.

#### **Details and Considerations**

**Resolution Impact**

* **Pixel Density:**
  * Standard HD cameras have a resolution of **1920 x 1080 pixels**, providing sufficient detail for general surveillance.
  * At greater distances, vehicles occupy fewer pixels, potentially reducing detection accuracy.
* **Image Quality:**
  * Clarity diminishes with distance due to factors like atmospheric conditions and lens limitations.
  * **Example:**
    * A vehicle at 25 meters may appear with less detail, affecting recognition capabilities.

**Lighting Conditions**

* **Importance of Adequate Lighting:**
  * Essential for maintaining image quality, especially at maximum distances.
  * Low-light conditions can significantly impact detection performance.
* **Solutions:**
  * **Supplemental Lighting:**
    * Install additional lighting to enhance visibility during nighttime or low-light scenarios.
  * **Camera Features:**
    * Use cameras with low-light sensitivity or infrared capabilities.

**Use Cases**

* **Urban Environments:**
  * Ideal for city streets, parking lots, and areas where vehicles are within close proximity.
* **Entry and Exit Points:**
  * Effective for monitoring gates or checkpoints where vehicles pass near the camera.

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### **4K Camera**

* **Effective Detection Distance:** Up to **40 meters** (approximately **131 feet**).
* **Recognition Capabilities:**
  * **Vehicle Detection:** Reliable across the extended range.
  * **Vehicle Classification:** Detailed identification, including make and model, within **25 meters** (approximately **82 feet**).
  * **License Plate Recognition:** Enhanced capabilities, potentially effective up to **20 meters** (approximately **66 feet**), depending on conditions.

#### **Details and Considerations**

**Higher Resolution Benefits**

* **Pixel Density:**
  * 4K cameras offer a resolution of **3840 x 2160 pixels**, quadrupling the pixel count of HD cameras.
  * Increased detail allows for better detection and recognition at greater distances.
* **Digital Zoom:**
  * Enables magnification of specific areas without significant loss of image quality.
  * **Example:**
    * Zooming in on a distant vehicle to read a license plate or identify features.

**Image Quality Factors**

* **Lens Quality:**
  * High-quality optics are crucial to maximize the advantages of higher resolution.
  * Lenses with low distortion and high light transmission improve overall image clarity.
* **Sensor Performance:**
  * Advanced sensors with higher dynamic range handle varying lighting conditions better.

**Use Cases**

* **Highways and Expressways:**
  * Suitable for monitoring fast-moving traffic over longer distances.
* **Large Facilities:**
  * Effective in expansive areas like airports, industrial complexes, or large parking lots.

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### **Factors Influencing Detection Distance**

Understanding the variables that affect detection distance enables you to optimise camera placement and select the right equipment for your needs.

#### **Resolution and Pixel Density**

* **Pixels on Target (POT):**
  * The number of pixels representing a vehicle directly impacts detection accuracy.
* **Minimum Requirements:**
  * **Detection:** At least **25 pixels per meter**.
  * **Classification:** At least **40 pixels per meter**.
  * **Identification (e.g., license plates):** At least **80 pixels per meter**.

<div align="left"><figure><img src="https://2528410345-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FB6Ja4QlJv7qMfQlUtujK%2Fuploads%2FUySsVjonqJP7HEYsNsuA%2FPixels%20on%20Target%20%20(2).jpeg?alt=media&#x26;token=d6ed1e1c-c6fa-4010-b780-bb22cf502803" alt="" width="563"><figcaption><p>Example of pixels on target. Number of pixels per meter required for accurate detection.</p></figcaption></figure></div>

#### **Lens Quality and Aperture**

* **Focal Length:**
  * Determines the magnification and field of view.
  * Longer focal lengths (e.g., telephoto lenses) focus on distant objects but reduce the field of view.
* **Aperture (F-number):**
  * Lower F-number indicates a larger aperture, allowing more light to reach the sensor.
  * Larger apertures enhance low-light performance.

#### **Sensor Sensitivity**

* **Sensor Size:**
  * Larger sensors capture more light, improving performance in low-light conditions.
* **Technological Advancements:**
  * Features like back-illuminated sensors and enhanced dynamic range contribute to better image quality.

#### **Environmental Conditions**

* **Lighting Variations:**
  * Inconsistent lighting can affect detection accuracy.
* **Weather Conditions:**
  * Fog, rain, snow, and dust can reduce visibility.
* **Mitigation Strategies:**
  * Use cameras with Wide Dynamic Range (WDR) and weather-resistant features.
  * Install protective housings or environmental shields.

#### **Installation Factors**

* **Mounting Stability:**
  * Vibration or movement can cause blurring, especially at higher magnifications.
  * Use sturdy mounts with vibration dampening if necessary.
* **Camera Alignment:**
  * Precise positioning ensures the area of interest is within the optimal detection range.
* **Obstructions:**
  * Avoid physical barriers that could block the camera's view.

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### **Practical Recommendations**

#### **Camera Selection**

* **Assess Your Needs:**
  * **Standard HD Cameras:**
    * Choose for areas where vehicles are within **25 meters** and high detail is not critical.
    * Cost-effective for general monitoring.
  * **4K Cameras:**
    * Opt for when detailed recognition at longer distances is required.
    * Justify higher costs with enhanced capabilities.

#### **Optimise Camera Settings**

* **Resolution Settings:**
  * Ensure cameras are configured to their maximum resolution.
* **Compression Techniques:**
  * Use efficient codecs (e.g., H.265) to reduce bandwidth without compromising quality.
* **Frame Rate:**
  * Higher frame rates (e.g., **25-30 fps**) capture fast-moving vehicles more effectively.

#### **Testing and Validation**

* **Conduct Field Tests:**
  * Verify detection distances under actual environmental conditions.
* **Adjust Based on Results:**
  * Fine-tune camera settings and positioning as needed.
* **Regular Monitoring:**
  * Continuously assess performance and make adjustments for seasonal changes.

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By understanding object detection distances and the factors that affect them, you can strategically plan your camera installations. This ensures that the vehicle monitoring system operates efficiently, providing accurate detections and reliable data for your specific applications.
