/match-reference — Match a Reference Image

Look at a reference image and the current timeline frame side by side, then adjust the grade to match the reference.

Arguments

The user provides a path to a reference image. This can be:

• A still frame from another project
• A film still or screenshot
• A LUT preview image
• Any image that represents the target look

Workflow

1. Switch to Color page

Use resolve_switch_page("color").

2. Export current frame in sRGB

Use resolve_export_frame to export to /tmp/resolve_match_current.png.

Convert to sRGB with ffmpeg:

ffmpeg -y -i /tmp/resolve_match_current.png \
  -vf "colorspace=all=bt709:iall=bt2020:fast=1" \
  -color_primaries bt709 -color_trc iec61966-2-1 -colorspace bt709 \
  /tmp/resolve_match_current_srgb.png 2>/dev/null

Fallback if that fails:

ffmpeg -y -i /tmp/resolve_match_current.png -pix_fmt rgb24 /tmp/resolve_match_current_srgb.png 2>/dev/null

3. Read both images

Use the Read tool on both:

• /tmp/resolve_match_current_srgb.png (current timeline frame)
• The user's reference image path

Claude can see both images simultaneously and compare them visually.

4. Get current grade state

Use resolve_node_overview to see all nodes. Use resolve_get_cdl to read current CDL. Use resolve_get_node_count for node count.

5. Analyze the difference

Compare the reference to the current frame across these dimensions:

Overall exposure: Is the reference brighter/darker? Contrast curve: Is the reference higher/lower contrast? Are blacks lifted or crushed? Color temperature: Is the reference warmer or cooler? Shadow color: What hue are the shadows in the reference? (teal, blue, purple, neutral) Highlight color: What hue are the highlights? (warm, cool, neutral) Midtone color: Any color shift in the midtones? Saturation level: More or less saturated than current? Specific color shifts: Any obvious color grading choices (orange/teal, bleach bypass, cross-process, etc.)

6. Calculate CDL adjustments

Map the visual difference to CDL values:

• Slope (R,G,B) — match overall brightness and color balance
• Offset (R,G,B) — match shadow color and black level
• Power (R,G,B) — match midtone density and color
• Saturation — match overall saturation level

Work on the last node in the chain. If the existing grade is complex, add a new node for the match adjustment.

Apply with resolve_set_cdl.

7. Verify the match

Export a new frame after adjustments:

• /tmp/resolve_match_after.png → convert to sRGB
• Read it alongside the reference
• Compare: does it match closer now?
• If not close enough, make additional adjustments
• Iterate up to 3 times to refine the match

8. Report

Tell the user:

• What the reference look is characterized by (e.g., "warm highlights, teal shadows, lifted blacks, moderate contrast")
• What CDL values were applied
• How close the match is (exact match is impossible with CDL alone — note if a LUT would get closer)
• Suggest a LUT if the look requires more than CDL can achieve (e.g., film emulation, S-curve, heavy color shifts)

Limitations

CDL is a linear correction (slope, offset, power, saturation). It cannot replicate:

• S-curve contrast (use a LUT or Resolve curves)
• Selective color shifts (use qualifier/HSL tools manually)
• Film grain, halation, bloom (use OFX plugins)
• Heavy cross-process looks (use a LUT)

If the reference requires these, describe what additional manual adjustments the user should make.

Example Interactions

User: /match-reference /Users/me/Desktop/film_still.jpg → Read both images, analyze difference, apply CDL to match, verify.

User: /match-reference ~/Pictures/teal_orange_look.png → Match the teal/orange look from the reference.

User: /match-reference /Volumes/Stills/hero_frame_graded.tiff → Match a previously graded hero frame from another project.