Bit-depth conversion (16→8)

Down-convert 16-bit pixel data to 8-bit for sharing or display.

Problem

Many DICOM images store pixel data at 16 bits per pixel (Bits Allocated = 16, Bits Stored = 12-16). While this preserves the full Hounsfield Unit range for diagnostic use, 8-bit consumers (web viewers, PNG export, some ML frameworks) require 8-bit data. The conversion reduces bit depth from 16 to 8 while applying the current window/level to maximize contrast in the relevant tissue range.

Steps

1. Open the file (⌘O).

2. Open Pixel Operations — ⌘K → “Pixel operations…”.

3. Select Bake W/L — this operation performs both window/level baking and bit depth conversion in one step.

4. Click Apply transform.

5. Verify:

   • Bits Allocated (0028,0100) → 8
   • Bits Stored (0028,0101) → follows Bits Allocated
   • High Bit (0028,0102) → 7 (0-indexed for 8 bits)
   • Photometric Interpretation (0028,0004) → MONOCHROME2

Expected Result

• All bit-depth tags reflect 8-bit output.
• Pixel values are windowed to the current W/L setting before truncation.
• Output file size is approximately half the original (8 bits vs 16 bits per pixel).
• The Modality LUT tags are removed.
• This is the same workflow as Window/Level Baking (4.4) — the bit depth conversion is an inherent consequence.