My bad ... I was not thinkking of Imagemagick but denoisiners in general. And to conclude ... I will denoise just before exporting to video ... Cheers E
--- On Sat, 9/4/11, [email protected] <[email protected]> wrote: From: [email protected] <[email protected]> Subject: Re: [CinCV] Denoisers To: [email protected] Date: Saturday, 9, April, 2011, 4:08 AM My remark was not related to the progressive or interlaced nature of the frames you want to process. I just made the assumption (implicitly) that imagemagick would process those still images (every TIFF file) independantly from the others. This tools is meant for still image processing, not for video, isn't it ? But the definition of "noise" is not exactly the same in a still image and in video (either progressive or interlaced). Still image processors work only in the spatial domain ie. they compare the values of adjacent pixels to decide what is "noise" or what isn't. Spatial denoisers tend to soften the image, by removing little details (these details effectively being noise or "real detail" aka. "grain"). Denoisers designed for video have the advantage that they can also work in the temporal domain, ie. they compare the values of the same pixels (or group of pixels) between different frames to decide what can be considered as "noise" and should be removed. Temporal denoisers usually reduce flicker and little variations in a pixel's values between different frames. Spatio-temporal denoisers can combine the advantages of the two approaches. The best of them can determine and analyze motion vectors in the video to perform "motion-compensated" denoising, which is the most effective kind of denoising on video (not when you watch the video frame by frame, but when you play it at it's original framerate). The result can be outstanding. I've neverd heard of a free tool able to denoise RGB video in the spatio-temporal domain (it may exist in costly professional software, though). ----- Mail Original ----- De: "Edouard Chalaron" <[email protected]> À: [email protected] Envoyé: Vendredi 8 Avril 2011 11h01:45 GMT +01:00 Amsterdam / Berlin / Berne / Rome / Stockholm / Vienne Objet: Re: [CinCV] Denoisers Well ... not really Julien... or I don't think so. What is the difference between scanned films (16mm for say) and progressive video frames ? apart from the colour space of course... Cheers E The drawback of denoising a still images sequence is that you will denoise only in the spatial domain, not temporal nor spatio-temporal (the latest being the most effective for video --> motion compensated denoising). _______________________________________________ Cinelerra mailing list [email protected] https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
