Feature

AI Face Detection

✨ A Complete Guide to AI Face Detection & ROI Masking in PhenoCapture AI

PhenoCapture AI’s AI Face Detection & ROI Masking tool brings high-speed facial detection, landmark extraction, and automated region-of-interest (ROI) masking directly to your workspace. Powered by an optimized ONNX deep learning engine, this tool instantly locates faces, calculates head tilt angles, and extracts 6-point facial landmarks across everything from close-up portraits to high-resolution group photos.

Whether you need to automatically anonymize faces with blur or mosaic filters, extract facial keypoint coordinates for quantitative analysis, or stamp custom visual overlays onto your images, this tool handles the entire workflow in milliseconds.

💡 Key Features

  • Instant Auto-Detection & CPU Acceleration: Powered by the ONNX Runtime with CPU Boost optimizations, face detection runs automatically the moment you open the tool—delivering rapid inference without freezing your UI.
  • Smart Image Tiling for High-Res Photos: Detecting small faces in ultra-high-resolution or group photos is effortless. By enabling the Tiling Method (High-Res Image) option, the software automatically scans the image in smaller sections and merges the results cleanly.
  • 6-Point Facial Landmarks & Head Tilt Calculation: For every detected face, the AI extracts 6 key facial landmarks—Left Eye, Right Eye, Nose Tip, Mouth Center, Left Ear, and Right Ear—and automatically computes the Head Tilt (Roll Angle in degrees).
  • Rotated Ellipse vs. Rectangle ROI Shapes: Choose between a standard Rectangle or a Rotated Ellipse that automatically tilts to match each person’s head angle for natural, tight coverage around faces.
  • One-Click Transfer to Workspace Selection Mask (Apply to Mask): Need to blur, pixelate, or color-correct only the faces in a photo? Clicking [Apply to Mask (ROI)] converts all checked faces into an active binary selection mask in your main workspace—ready for immediate Gaussian Blur, StackBlur, Mosaic, or color adjustments!
  • Fully Independent Live Preview Options: Toggle Bounding ROI, Face ID (#), Confidence Score, and 6-Keypoints completely independently. Customize box colors, text fonts, and label colors with instant live preview updates—without re-running the AI detection.
  • Excel-Ready Data Export (Separated X, Y Columns): The results table outputs Face ID, Confidence, X, Y, Width, Height, Tilt (°), and separate X and Y columns for all 6 facial keypoints—making it easy to copy to your clipboard or save as a CSV file for Excel analysis.

🛠️ How to Use the AI Face Detection Tool

Step 1: Prepare Your Workspace and Selection (Optional)

Load your image into the main workspace. If you only want to detect faces within a specific region, use the selection tools to draw a boundary mask first. Otherwise, the AI will scan the entire image.

Step 2: Launch & Adjust Detection Parameters

Open the Face Detection & ROI Masking tool. The AI will automatically run an initial scan as soon as the window opens!

  • If needed, adjust the Confidence Threshold (to filter out uncertain predictions) or NMS Threshold (to prevent overlapping detections), check Tiling Method (High-Res Image) for large photos, and click [Detect Faces] to re-scan.

Step 3: Filter Faces & Customize Visual Overlays

Once detection is complete, all detected faces are listed in the left panel and detailed in the coordinate grid:

  • Use Select All or check/uncheck individual faces (e.g., Face #1, Face #2) in the Detected Faces list to include or exclude specific individuals.
  • Independently check or uncheck Show Bounding ROI, Show Face ID (#), Show Confidence, and Show 6-Keypoints to display only the exact visual elements you want.
  • Switch between Rotated Ellipse and Rectangle under ROI & Mask, and customize the ROI color or label font at any time.

Step 4: Choose Your Output Action (Mask, Export, or Draw)

Depending on your goal, finish your workflow with one of three actions:

  • To Blur, Anonymize, or Edit Faces: Click [Apply to Mask (ROI)]. The preview overlays will be removed, and the selected faces will be converted into an active selection mask on your workspace image. You can then immediately apply Gaussian Blur, Mosaic, or any image filter exclusively to the detected faces!
  • To Export Coordinate & Landmark Data: Click [Save CSV] or [Copy Table] to export the bounding boxes, head tilt angles, and all 12 separated X/Y keypoint coordinates directly to Excel.
  • To Stamp Overlays onto the Image: Click [Draw on Image] to permanently render the selected boxes, IDs, and keypoints onto your workspace canvas (with full Undo Engine support).

💡 Pro Tip: How to Blur Faces for Privacy Protection in Seconds

Combining AI Face Detection with PhenoCapture AI’s blur filters is the fastest way to anonymize portraits or group photos while keeping the background crystal clear:

  1. In the Face Detection & ROI Masking window, select Rotated Ellipse under ROI & Mask and check the faces you want to blur in the Detected Faces list.
  2. Click [Apply to Mask (ROI)]. The checked faces will instantly become active elliptical selection regions (marching ants) on your main workspace canvas.
  3. Open any blur or privacy filter—such as Gaussian Blur, Stack Blur, or Mosaic—adjust the strength slider with live preview, and click [OK]. Only the masked face regions will be smoothly blurred!


By combining rapid AI face detection with rotated elliptical ROI masking, PhenoCapture AI makes automated face anonymization, portrait region selection, and facial coordinate extraction faster and more intuitive than ever!