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Very good comment, though broadcast and video are much harsher environments for graphics than a computer monitor. The resolution is lower as you point out, espe

by ssp 14y ago

Very good comment, though broadcast and video are much harsher environments for graphics than a computer monitor. The resolution is lower as you point out, especially chroma resolution, and there may be interlacing and/or compression going on too. Each of these makes heavier blurring more desirable for high-frequency images such as text. Regarding this: So a controlled amount of blur, and I'm not talking about anti-aliasing, it's worth pointing out that anti-aliasing is a form of blur, but most software usually uses a box filter which is a really a poor filter. I have some demonstration images here: http://www.freedesktop.org/~sandmann/tigers http://www.freedesktop.org/~sandmann/tigers Compare these two especially: http://people.freedesktop.org/~sandmann/tigers/tiger-box.png http://people.freedesktop.org/~sandmann/tigers/tiger-box.png http://people.freedesktop.org/~sandmann/tigers/tiger-jinc-gamma-wide-stroke.png http://people.freedesktop.org/~sandmann/tigers/tiger-jinc-ga... The first one is what cairo produces; the second is improved in three ways: (1) The antialiasing filter is based on the Jinc function rather than a box, (2) white and black are offset slightly from the top and bottom, and (3) the compositing is done in linear light, not sRGB. The strokes in the second image are also somewhat wider in order to compensate for the lighter appearance that gamma-aware compositing produces.

commieneko 14y ago
I'm using the terminology pretty loosely, trying to match the tone of the discussion here. This is a casual comment. And really too long a one at that. When I'm saying anti-aliasing I'm really meaning super sampling and weighted assignment of brightness values. There's a lot of ways to do that, all with their own artifacts and advantages. Filtering is used as a catch all for operations that reduce image sampling and display artifacts. Most website designers will be using Photoshop and its blur and Gaussian blur filters. Those work just fine. If you need anything fancier, or can make use of it, you probably don't need to have read my comment. For this type of work I've found that techniques developed by oil painters over the centuries work just fine. A little math goes a log way. My point is that if you are fiddling with pixels, you probably aren't looking at the whole image, and probably should be. Counter intuitive as it may seem, sharpness is not always your friend. You've got bigger things to worry about. In the "real world" nearly everything we look at is seen by reflected light, with pigments subtracting frequencies and value from the available light. Edges come and go due to characteristics of our visual system. Brightness levels are incredibly wide compared to what we get on the screen. On a computer screen we are looking at emitted light, with a very strange, and constrained gamut. Edges and areas are defined by additively mixed samples and other artifacts. Go outside some evening, just as the sun is setting, and walk through a residential neighborhood with a lot of trees, houses and such. Very peaceful. Except for the neighbor who has his living room window open and lets his TV shine like a demon in the night, destroying the ambience and mood. (And don't get me started talking about audio!) A good designer knows how to use those characteristics, the limitations of his/her medium, to recreate the experience of the world, or to control them to create something different that serves their purposes. It's why a painting can look better than even a very good photograph. Or why a highly manipulated photograph can look better than an un-staged one. Portrait studios are not the site of a documentary :)

by ssp 14y ago

commieneko 14y ago

I'm using the terminology pretty loosely, trying to match the tone of the discussion here. This is a casual comment. And really too long a one at that. When I'm saying anti-aliasing I'm really meaning super sampling and weighted assignment of brightness values. There's a lot of ways to do that, all with their own artifacts and advantages. Filtering is used as a catch all for operations that reduce image sampling and display artifacts. Most website designers will be using Photoshop and its blur and Gaussian blur filters. Those work just fine. If you need anything fancier, or can make use of it, you probably don't need to have read my comment. For this type of work I've found that techniques developed by oil painters over the centuries work just fine. A little math goes a log way. My point is that if you are fiddling with pixels, you probably aren't looking at the whole image, and probably should be. Counter intuitive as it may seem, sharpness is not always your friend. You've got bigger things to worry about. In the "real world" nearly everything we look at is seen by reflected light, with pigments subtracting frequencies and value from the available light. Edges come and go due to characteristics of our visual system. Brightness levels are incredibly wide compared to what we get on the screen. On a computer screen we are looking at emitted light, with a very strange, and constrained gamut. Edges and areas are defined by additively mixed samples and other artifacts. Go outside some evening, just as the sun is setting, and walk through a residential neighborhood with a lot of trees, houses and such. Very peaceful. Except for the neighbor who has his living room window open and lets his TV shine like a demon in the night, destroying the ambience and mood. (And don't get me started talking about audio!) A good designer knows how to use those characteristics, the limitations of his/her medium, to recreate the experience of the world, or to control them to create something different that serves their purposes. It's why a painting can look better than even a very good photograph. Or why a highly manipulated photograph can look better than an un-staged one. Portrait studios are not the site of a documentary :)