14 Free HDR Screenshot Tone Mapping and ffmpeg Steam Capture Tools (2026)

Core HDR-to-SDR engine—zscale + tonemap converts BT.2020/PQ masters to clean Rec.709 store frames without clipped highlights.
CTA: tone-map before you downscale to 616×353, never after

Tone-map filter reference—tonemap=hable / mobius and zscale primaries/transfer options that decide whether bloom survives.
Pro tip: compare hable vs reinhard on the brightest frame first

Banding killer—generate a per-image palette then apply dither=bayer / sierra2_4a so smooth skies stop posterizing after downscale.
Order: tonemap → dither → export

Bit-depth proof—read pix_fmt, color primaries, and transfer of the source so 8-bit vs 16-bit is a receipt field, not a guess.
Gate: record source_pix_fmt in the tone receipt

Histogram + quantize toolkit—-format %[histogram] and -colors reveal banding before you ship; -dither FloydSteinberg smooths gradients.
Beginner: run a histogram diff pre/post regrade

Flag reference—-dither, -colors, -depth, and -resize so the capsule downscale is scriptable and identical every refresh.
Pro tip: pin the exact resize filter (Lanczos) in the receipt

Node-based HDR tone map—free edition includes color-managed HDR→SDR and a Resolve HDR Tone Mapping node for the reference master before ffmpeg export.
Use for: hero capsules that need eyes-on grading

Capsule dimension contract—header, small, and library capsule sizes so your tone-mapped export lands at the right pixels (616×353 header capsule).
Fail when: banding only appears after the store downscale

Authoritative tone-mapping reference—the EOTF and tone-mapping math behind why naive HDR clipping bakes false bloom into SDR captures.
Read when: choosing a tone-map curve, not copying presets blind

December art pass narrative—how to downscale winter HDR masters without false bloom, step by step, with the tone receipt spine.
Format ladder: blog = art pass; this list = tool bookmarks

Three-swatch safe-zone cross-check—lock a capsule palette so tone-mapping keeps brand colors and the sale sticker stays readable.
Pair with: ImageMagick histogram before palette lock

Recovery help—diagnose and fix banding that only shows after the 616×353 downscale following an HDR regrade.
Run: the 616×353 squint test from this help page

BUILD_RECEIPT milestone—promote screenshot_tone_receipt_v1.json after DaVinci HDR→SDR tone map and SDR Steam capture.
Cousin schema: winter_capsule_tone_receipt_v1

Downstream QA hub—once capsules pass the tone receipt, run the store-page QA list so localized capsules and captions ship clean too.
Order: tone map → capsule QA → localization freeze