Black-box redaction

Apply opaque black-box redaction over sensitive pixel regions.

Problem

You’ve identified sensitive pixel regions — either through OCR detection or manual inspection — and now you need to apply opaque black-box redaction over those areas. The redaction tool lets you draw rectangular bounding boxes directly on the DICOM image. When exported, those regions are filled with black pixels in the output file.

Steps

Draw a Redaction Box

1. Open your DICOM file (⌘O) and switch to Anon mode (⌘2).

2. Activate the Redact tool — click the black-box redaction tool in the toolbar. The button highlights to indicate the tool is active.

3. Draw a rectangle on the image — click and drag on the Cornerstone viewport canvas:

   • Move the pointer to the top-left of the area you want to redact
   • Press and hold the mouse button
   • Drag diagonally to the bottom-right of the area
   • Release to finalize the rectangle

4. Verify the region is registered — the redaction regions counter updates to show (1). The bounding box is displayed as an overlay on the image.

5. Export — click Apply & Export to write the redacted DICOM file with black-filled regions.

Expected Result

• One redaction region is registered after drawing a rectangle on the canvas.
• Coordinate clamping: If you drag past the image boundaries (e.g. start near the right edge and drag well outside), the coordinates are clamped to the image dimensions — no errors, no array-out-of-bounds.
• Zero-area rejection: A single click (without dragging) does not create a redaction region. The counter stays at (0).
• Near-edge boxes: Boxes drawn very close to the top-left corner (xMin/yMin near zero) are clamped to [0, 0] on export.
• Apply & Export produces a valid DICOM file with the redacted regions filled black. Clinical pixel data outside the boxes is preserved.
• You can draw multiple redaction boxes on the same frame. Each one is registered independently.