Image capture in automated vision systems often relies on external triggers, which introduce complexity in hardware design and software synchronization. The self-trigger function in e-con Systems’ See3CAM_37CUGM, based on the Sony® Pregius S™ IMX900 sensor, eliminates this dependency by detecting trigger conditions internally.
It enables selective image acquisition based on predefined threshold parameters by defining sensing and capturing zones within the image sensor’s active pixel array.
In this blog, you’ll understand how this powerful IMX900-based camera’s self-trigger mode works to ensure smooth automated image capture.
Understanding Self-Trigger Mode in e-con Systems’ See3CAM_37CUGM
With the self-trigger feature, See3CAM_37CUGM can enhance image acquisition in dynamic environments by reducing reliance on external signaling mechanisms. It also helps maintain control over exposure and gain settings for both sensing and capturing areas. Exposure is based on the number of lines configured in the sensing area. Gain alone can be configured differently for both the sensing and the capturing area.
Defining sensing and capturing areas
The self-trigger function operates by partitioning the sensor’s active pixel region into two defined sections:
- Sensing area: Monitors pixel intensity levels and determines if a triggering condition has been met.
- Capturing area: Captures the image frame when the triggering event occurs.
The system continuously analyzes pixel intensity in the sensing area. If a certain number of pixels exceeds the defined threshold, an internal trigger is generated, leading to image capture in the designated capturing area. This helps detect objects that meet specific contrast or brightness conditions without any sort of manual intervention.
How See3CAM_37CUGM’s Self-Trigger Mode Works
The self-trigger function offers flexible settings for customizing detection and capture parameters. First, the user can assign one sensing area for monitoring pixel intensity changes and one capturing area for image acquisition upon meeting the trigger conditions. Each pixel in the sensing area can be assigned a level threshold that determines whether it contributes to the triggering event.
It is important to note the number of pixels that must exceed the level threshold before triggering an image capture is set as the count threshold.
Then, e-con Systems’ See3CAM_37CUGM provides the capturing frame separately. The sensing frame will not be transferred to the host. Instead, the users can configure the sensing frame area.
Configuring self-trigger thresholds
The self-trigger system operates using two key threshold parameters:
- Self-trigger level threshold
- Self-trigger count threshold
Each threshold type contains both high and low values, enabling fine-tuned control over the triggering mechanism.
Self-trigger level threshold
The level threshold determines how individual pixels in the sensing area contribute to the trigger condition. Two parameters define this threshold:
- SELFTRIG_TH_H (High)
- SELFTRIG_TH_L (Low)
If the pixel intensity falls above the user-configured SELFTRIG_TH_H (High) threshold value, it is considered a Bright pixel. If it falls below the SELFTRIG_TH_L (Low) threshold value, then it is considered a dark pixel. This allows a controlled method for detecting variations in image brightness while filtering out irrelevant intensity changes.
For instance, in a barcode scanner on a conveyor belt, the self-trigger function can identify barcodes by monitoring brightness and contrast variations in the sensing area. When a barcode enters the designated zone and its pixel intensity surpasses the defined threshold, the system captures an image to decode the barcode without requiring an external trigger mechanism.
Self-trigger count threshold
The count threshold defines the number of pixels that must exceed the level threshold before triggering image capture. Two parameters govern this process:
- SELFTRIG_CNT_TH_H (High)
- SELFTRIG_CNT_TH_L (Low)
If the number of pixels exceeding the level threshold surpasses one of these count values, the capturing process is initiated.
For example, in Intelligent Transportation Systems (ITS), traffic monitoring cameras can use the self-trigger function to detect vehicles at intersections by analyzing headlight intensity. The sensing area tracks brightness variations, and once the number of pixels surpasses the defined count threshold, the system captures an image of the vehicle for automated traffic analysis or violation detection.
See3CAM_37CUGM: A Global Shutter Camera for High-Performance Imaging
e-con Systems has been designing, developing, and manufacturing OEM cameras since 2003. See3CAM_37CUGM is the latest addition to our global shutter camera lineup, powered by on-camera HDR support. The onboard FPGA processes RAW sensor data, optimizing image capture under varying lighting conditions.
To explore e-con Systems’ full range of camera solutions, visit our Camera Selector Page.
For assistance in selecting and integrating the right camera for your embedded vision system, reach out to camerasolutions@e-consystems.com.
Suresh Madhu is the product marketing manager with 16+ years of experience in embedded product design, technical architecture, SOM product design, camera solutions, and product development. He has played an integral part in helping many customers build their products by integrating the right vision technology into them.