On Wed, 23 Jul 2025 05:30:57 +0000 Sarthak Indurkhya via ffmpeg-devel <ffmpeg-devel@ffmpeg.org> wrote: > Thank you for the thoughtful feedback. > > Advantages over vf_libplacebo’s inverse tone mapping: > > 1. Algorithmic Differentiation: > My filter is based on a novel local adaptation + inverse tone mapping > strategy specifically tailored to enhance perceptual brightness while > preserving spatial detail. > > My implementation uses: > > * Local bilateral filtering over luminance for content-adaptive > scaling. > * Dynamic inverse tone mapping via (R / (1 - R))^1/n style > reparameterization. > * Chromatic scaling to preserve original hues during dynamic range > expansion. > 1. Color Fidelity & HDR Metadata: > * The filter performs color space conversion from BT.709 to BT.2020 > explicitly and integrates PQ transfer function encoding with full support for > mastering metadata (mastering_display_primaries, content_light_level, etc.). > * It incorporates localized tone curve shaping, white balance, and > chroma boosting that target HDR presentation aesthetics more directly. > 2. Customizability: > * Parameters like sigma_spatial, sigma_range, n, and hdr_max allow > users to tailor the HDR expansion according to scene content or output > requirements.
None of that sounds different from what vf_libplacebo is doing. Do you have an example output somewhere that we could compare? > > I agree that a GPU-based real-time implementation would be valuable. The > algorithm I've used is highly parallelizable and very well-suited for > implementation as a GPU shader > > > Get Outlook for Mac <https://aka.ms/GetOutlookForMac> > > From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> on behalf of Kacper > Michajlow <kaspe...@gmail.com> > Date: Saturday, 19 July 2025 at 8:18 PM > To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org> > Subject: Re: [FFmpeg-devel] [PATCH] avfilter: add inverse tone mapping > EXTERNAL: Use caution when clicking on links or opening attachments. > > > On Sat, 19 Jul 2025 at 16:13, Sarthak Indurkhya via ffmpeg-devel < > ffmpeg-devel@ffmpeg.org> wrote: > > > Hello FFmpeg developers, > > This patch introduces a new video filter called inversetonemap for FFmpeg. > > The filter performs SDR to HDR conversion by mapping SDR BT.709 video to > > HDR BT.2020 PQ, using local adaptation and inverse tone mapping. The goal > > is to provide a simple, flexible tool for upconverting SDR content for HDR > > displays, with local adaptation, tone curve sensitivity, and chroma > > processing. > > > > Please review. > > Thanks, > > Sarthak > > > > > > > Interesting. Could you describe what are the advantages of the new filter, > compared to existing solutions like vf_libplacebo inverse tone mapping? > Additionally if there is a big gap in libplacebo's inverse tone mapping > quality would you be interested in improving the libplacebo implementation > in addition to this filter? I think there would be a gain in having real > time gpu implementation too. > > - Kacper > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fffmpeg.org%2Fmailman%2Flistinfo%2Fffmpeg-devel&data=05%7C02%7Csindurkhya%40adobe.com%7Cae51c0c89a19441126c408ddc6d348ef%7Cfa7b1b5a7b34438794aed2c178decee1%7C0%7C0%7C638885332956664603%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=c7Ot4ow8uXKRfk%2F05O9B5bCkxjynTUwg90S%2Bf5uJeYU%3D&reserved=0<https://ffmpeg.org/mailman/listinfo/ffmpeg-devel> > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
