LUT Cube Analyzer Free

• LUT Type Auto-Detection — a colour-coded banner classifies the LUT automatically: Identity, Log→Linear, Linear→Log, S-Curve Contrast, Low Contrast / Matte, Monochrome, or Creative Look, with inline tags for cast direction, saturation behaviour, and hue activity
• R / G / B Channel Curves — neutral-axis sweep for each channel; X = input (0–100%), Y = output. Each panel shows per-curve inline stats: min/max delta, average deviation, black-point and white-point offsets, and S-curve detection
• All Channels Overlay — superimposes R, G, and B on one wide canvas; toggle individual channels via the R / G / B visibility pills. A Y′ Luminance trace (toggle) shows the weighted brightness response independently of colour
• Saturation vs Input Luminance — average chroma ratio across 6 hue angles at each tonal level. 1.0× = identity, >1.0× = saturation boost, <1.0× = desaturation. Inline stats flag the saturation character in shadows, midtones, and highlights
• Hue Shift vs Input Hue — output hue rotation in degrees across all 360 input hues; 0° = no shift. A rainbow strip labels each input hue. Use this to detect skin-tone rotation (15–45° orange–red zone) or intentional creative remapping
• Pinned Markers — click anywhere on a curve canvas to drop a vertical pin; the pin reads the exact output value and Δ delta at that input level. Pin at 6.3% for black point, 50% for midtones, 92.2% for Rec.709 legal white. Press Clear Pins to remove all
• Freeze Curves — saves the current LUT's curves as a ghost reference (dashed, semi-transparent). Load a second LUT to overlay both grades simultaneously and compare divergence across every tonal zone without switching tabs
• Log X axis — switches the horizontal scale to logarithmic, spreading the shadow zone across the left half of the canvas for precision inspection of sub-10% tonal behaviour
• IRE Markers — dashed lines at Rec.709 legal black (6.3% = 16/255), 50 IRE midtone, and legal white (92.2% = 235/255) for broadcast-legal reference
• Clip Zones — shaded bands at the top and bottom 2% of output indicating probable clipping
• Curve Statistics & Correlation Panels — structured breakdown of lift / gamma / gain per channel, aggregate S-curve metric, endpoint offsets, and an inter-channel correlation matrix segmented by tonal zone

All curves use a neutral-axis sweep (R = G = B = input). Saturation and hue data are sampled from a full 6-hue sweep at each luminance step. Hover any canvas to read exact per-channel values and Δ delta at the cursor position.

• Upload Image — load a JPEG, PNG, or WebP file (up to 20 MB); the LUT is applied entirely in-browser; the image is never transmitted or stored
• Hue Matrix — always-on synthetic base; hue sweeps the full 0–360° spectrum horizontally while saturation and brightness vary vertically; exposes hue rotation, colour shifts, and cross-channel contamination at a glance
• Grey Ramp (toggle) — 21 neutral steps from black to white; any colour cast or uneven tonal response is immediately visible on a neutral input
• Skin Tones (toggle) — 8 skin-tone patches from fair to dark; essential for portrait and documentary LUT evaluation
• Banding Test (toggle) — 64 fine steps each in the shadow (0–25%) and highlight (75–100%) zones; reveals posterisation and banding artefacts
• Split drag — drag the centre divider to compare any proportion of original vs processed output; current split percentage shown below
• Pixel Inspector — hover anywhere on the canvas to read the exact 8-bit R / G / B values for the original and LUT-processed pixel side by side, plus the signed per-channel delta (Δ); useful for measuring precise colour shifts on skin tones, neutrals, and memory colours
• Clip Warning (toggle) — false-colour overlay on the LUT side: pixels whose output rounds to 255 in any channel are highlighted red (blown highlights); pixels where all channels round to 0 are highlighted blue (crushed shadows); works on both synthetic layers and uploaded images

Synthetic layers are generated in sRGB / Rec.709. Wide-gamut or log-input LUTs should also be evaluated in the Scopes tab for full-range accuracy

• Waveform — output level (0–100%) vs input value; use RGB Parade for per-channel lift/gain/gamma, Luma for a combined luminance trace, or Overlay to superimpose all three channels
• Vectorscope — chroma angle and saturation in Cb/Cr space; toggle 75% / 100% to scale the colour-bar target boxes; tight cluster near centre = low saturation, long radial axis = strong hue bias
• Histogram — value distribution per channel; switch between RGB and Luma modes; enable Log Scale to reveal detail in low-count bins
• CIE xy Chromaticity — output plotted on the 1931 CIE xy diagram; white dashed = sRGB / Rec.709 gamut, purple dashed = DCI-P3; D65 / D50 / D55 illuminant markers; Planckian locus 2000 K–10 000 K; red points = out-of-range output values
• Saturation Response — input chroma vs output chroma scatter; points above the diagonal = saturation boost, below = reduction; coloured by input hue to show which colour families are most affected

Waveform, Vectorscope, CIE xy, and Saturation Response use a phosphor-density renderer (P50 median normalisation) — brighter areas indicate higher point density. The Histogram uses a bar-chart renderer normalised to the channel peak.

• Tag pills — colour-coded fingerprint labels auto-generated from the analysis (e.g. Warm, Lifted Shadows, Film Emulation, Bleach Bypass, Orange & Teal)
• Radar chart — six axes scored 0–100: Strength, Contrast, Saturation, Warmth, Green Push, Smoothness
• Key metric tiles — six numerical readouts (Overall Strength, Contrast, Saturation, Colour Temp, Shadow Lift, Smoothness) with contextual colour coding
• DNA Signature — compact fingerprint hash (e.g. W4·+C5·L5·D3) for version control, catalogue search, and duplicate detection
• Hue Rotation Map — per-sector hue shift diagram across all 12 colour sectors; arrow direction = shift direction, arrow length = magnitude
• Skin Tone Preservation — score 0–100 measuring hue accuracy in the orange/red cluster (H 15–45°); critical for portrait and interview work
• Channel × Zone table — R/G/B average delta from identity across Shadows, Midtones, and Highlights; pinpoints selective grading and tonal imbalances
• Chromatic Neutrality — grey-axis integrity score measuring colour cast applied to neutral tones; high score = colour-safe for technical use
• Use Case Classifier — auto-detected workflow categories (Portrait-Friendly, Film/Cinematic, Log Conversion, Urban/Night, etc.)
• LUT Character — plain-language summary ready to paste into metadata files, project notes, or client delivery documents
• Warnings — flags highlight clipping (>1.0), shadow crushing (<0.0), near-blocked shadows, and overly strong LUT strength with opacity advice

Export the full DNA report as a PNG for documentation, client delivery, or LUT library cataloguing

• Side-by-Side / Overlay Mode — view RGB curves on separate canvases or superimposed on a single canvas (LUT A solid, LUT B dashed) for direct visual comparison
• Hover tooltip — move over any curve canvas to inspect the input value, R/G/B output, and per-channel delta at that point
• Similarity Score — luma-weighted perceptual distance sampled at 33³ = 35,937 grid points; 100% = identical, lower = more divergent, with a plain-language qualifier (e.g. "Very similar — same base grade, different strength")
• Delta Analysis — R/G/B mean absolute error across the full 3D gamut, displayed as bars on a fixed 20% scale for cross-LUT comparability
• Difference Curve — A−B per channel along the neutral axis (R = G = B); auto-scaled to the actual peak delta so subtle differences remain visible
• Swap A⇔B — reverse the comparison direction without reloading files

Both LUTs must be standard .cube format. LUT A is set from the current LUT automatically; Overlay Mode and Swap activate once LUT B is loaded. Export the full comparison as PNG.