From e577aba9fccfafcf4e44b8f1c508610df2081141 Mon Sep 17 00:00:00 2001 From: Niklas Haas Date: Sun, 15 Mar 2015 16:47:12 +0100 Subject: [PATCH] Generalize and rename the article --- Smoothmotion.md => Interpolation.md | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) rename Smoothmotion.md => Interpolation.md (84%) diff --git a/Smoothmotion.md b/Interpolation.md similarity index 84% rename from Smoothmotion.md rename to Interpolation.md index 316cdaf..84f5080 100644 --- a/Smoothmotion.md +++ b/Interpolation.md @@ -1,13 +1,11 @@ -Smoothmotion -============ +Interpolation techniques +======================== -Many people have come to misunderstand the functionality and purpose of -smoothmotion, going as far as confusing it with motion interpolation (such as -found in SVP or MVTools). +This article will cover a few of the standard techniques for temporal video frame interpolation, outlining in particular the difference between techniques like SVP/MVtools (also known as motion-based interpolation) and algorithms like smoothmotion. -To demonstrate the difference, we will look at what happens when trying to +To demonstrate the differences, we will look at what happens when trying to display a 24 Hz video file on 60 Hz monitor. This is the source file I will be using. For illustration, each video frame will appear as one horizontal line of the image. (So the vertical axis is the time axis) @@ -32,14 +30,16 @@ that the first frame will be shown 3 times, the second frame 2 times, the third As can be clearly seen, the inconsistent width results in a jagged appearance, which is a visualization of the phenomenon known as judder. -Motion interpolation -==================== +This technique is essentially like nearest neighbour upscaling - each frame simply picks the source frame that's closest to it in the original video source (rounded down). + +Motion-based interpolation +========================== -True motion interpolation algorithms like SVP, MVTools or the chips built into +Motion-based interpolation algorithms like SVP, MVTools or the chips built into various TV devices employ complex algorithms to try and recognize movement in -the video, and fill in the missing gaps as needed. +the video (motion vectors), and fill in the missing gaps as needed. This drastically alters the result - it's now one continuous motion, similar to a true 60 Hz clip. However, this comes at a cost - not only are the @@ -55,6 +55,8 @@ uses, which is usually shot at 24 Hz. Many people therefore subconsciously associate the visual appearance of 60 Hz content with soap operas, and thus think it looks worse. +This is essentially similar to "smart" upscaling filters, eg. NEDI or NNEDI3 - which are also expensive to compute and produce results that drastically alter the source image. + Smoothmotion ============