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Rockbox mail archiveSubject: Re: What Is Dithering?Re: What Is Dithering?
From: Bluechip <csbluechip_at_gmail.com>
Date: Sat, 18 Nov 2006 00:31:46 +0000 What a damn good utterly OT question. You'd think so, wouldn't you! However, in nature, even the smallest component of an object has the ability to absorb-versus-reflect any combination of light frequencies. So the smallest component might reflect all-red-frequencies and some of every other frequency - thus creating pink. Perhaps if you went as far as individual molecules you might find coloured dots, but you'll need a chemistry major to help you there. BC At 23:43 17/11/2006, you wrote: >Off Topic, but if you magnify an actual pink rose pedal enough, you will see >red dots and white dots. >Glenn >----- Original Message ----- >From: "Pieter Bos" <bos.pieter_at_gmail.com> >To: <rockbox_at_cool.haxx.se> >Sent: Friday, November 17, 2006 5:43 AM >Subject: Re: What Is Dithering? > > > >"Christopher Woods" <christof_at_infinitus.co.uk> wrote in message >news:007801c709fa$c51ffb70$4001a8c0_at_20hz... > > I guess a comparable analogy (best I can think of right now) > > would be if you take a large image, and resize it to a smaller size - if > > you > > have your settings to just go with each pixel's nearest neighbour when you > > shrink the image, you'll get uneven lines, jaggedy edges and it'll look a > > bit poor... Whereas if you set your image program to do bicubic or > > bilinear > > resizing, it looks at the pixels, their relationship to the ones next to > > them, and 'redraws' the image in a sense, blurring together areas for want > > of a better description, to produce a more aesthetically-pleasing result - > > lines look smoother, colours blend and gradient better... > > > >This analogy is more like increasing the time-resolution (sample rate) than >increasing the bit-depth. > >Perhaps a better analogy, speaking in terms of images, is exactly the same: >dithering. If you have only a limited number of colours, you can produce >more colours by drawing tiny dots of different colours. Our eyes will >automatically blend the colours, so we see a colour that is not actually >there but which is made up of a blend of the other colours. This is applied >for example in computer screens with a limited number of colours and in >printers - you can see the dots in every photo in every newspaper! > >You can try this yourself: Get two different colour pencils and draw lots of >dots on a piece of paper, alternating between both the colours.Make some >different areas, some with more dots with one colour, others with more dots >with the other colour. Make sure to draw the dots close together. Now look >at it from a distance. You will see different colours! You can try making a >drawing with this by changing the number of dots. > >If you have only one pencil available, just make drawings with dots, but >change the number of dots in the same area (eg. completely filled, half >filled...). > >In audio, the concept works almost the same. Think of the bit-depth of the >audio (16 bit...) as the number of available colours. If you want to match a >value that is not there, you can add some rapidly changing values close to >the value you want to match to gain a slightly better quality audio and a >bigger dynamic range. Now, you're performing dithering! > >Pieter Received on 2006-11-18 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |