Cropped ROI Endpoint (Classification Only)

OV10i Note

The OV10i supports classification models only. Segmentation features mentioned on this page are available on the OV20i and OV80i cameras.

Overview

The cropped_roi endpoint provides access to cropped Regions of Interest (ROIs) generated from classification results in Haystack running on the device.

Important: This endpoint works only for classification-type results. Segmentation type is not supported for ROI cropping through this endpoint.

The base URL format is:

http://{device-ip}/edge/haystack/cropped_roi/{classification_result_id}

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How It Works

When the camera completes a classification capture, The Node-RED flow dynamically constructs URLs for the cropped ROI images by pairing the device IP and classification result ID:

const imageUrl = `http://${baseUrl}/edge/haystack/cropped_roi/${result.id}`;

Each URL serves a cropped image corresponding to individual classification ROI, typically representing a single inspection.

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Node-RED Flow Summary

The ROI_Crop flow performs the following:

1. Extracts the Device IP

   • Parses the image_url field to find the IP (e.g., 192.168.0.101)
   • Stores it globally for reuse

2. Queries Latest Capture Data

   • Sends a GET request to the device’s PostgREST API:

     http://{device-ip}/postgrest/captures?select=...
     &order=id.desc&limit=1

   • Retrieves the most recent capture and all classification_result entries

3. Filters for Classification Results Only

   • Skips segmentation or alignment results

   • Iterates over each classification result:

     classificationResults.forEach(result => {
       const roiName = result.roi_result?.inspection_region?.name || `ROI_${result.id}`;
       const imageUrl = `http://${baseUrl}/edge/haystack/cropped_roi/${result.id}`;
       imageMap[roiName] = imageUrl;
     });

4. Outputs the Cropped ROI URLs

   • Saves all ROI image links to a global imageMap
   • Returns the list of latest cropped ROI image URLs

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Example Usage

Fetch a Cropped ROI Image

curl http://192.168.0.101/edge/haystack/cropped_roi/42 -o roi_42.jpg

Use in a Web Interface

<img src="http://192.168.0.101/edge/haystack/cropped_roi/42" alt="Cropped ROI 42">

Output Example

{
  "ROI_1": "http://192.168.0.101/edge/haystack/cropped_roi/1",
  "ROI_2": "http://192.168.0.101/edge/haystack/cropped_roi/2"
}

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Parameters

Parameter	Type	Description
device-ip	string	IP address of the camera (e.g. 192.168.0.101)

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Integration Flow

1. Acquire latest capture metadata via /postgrest/captures.
2. Identify available classification_result IDs.
3. Construct cropped ROI URLs for each result.
4. Display or download those images for analysis, training data, or QA inspection.

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Download Node-RED Flow

• ROI Crop Flow (JSON) - Complete Node-RED flow for extracting cropped ROI images
  • Import this flow directly into Node-RED to access cropped classification ROIs
  • Works with both OV10i and OV80i systems

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