AuthorTopic: Pixels And Art Glossary  (Read 20010 times)

Offline questseeker

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Re: Pixels And Art Glossary (v.0.5)

Reply #70 on: March 04, 2016, 03:25:45 pm
I'd expect more entries about techniques and patterns found both in tools and workflows and in images. Here's a first draft of two important ones:

Pillow Shading
Unrealistic shading of a smoothly curved object by distributing light and dark colors according to the shape of the object's outline instead of imagining and matching the shape of actual isophotes and the location of highlights; this normally results in approximately parallel and constant width color bands from the outline inwards, vastly different from the bunched up, interrupted, expanded and nonconvex shapes of correct shading.
A rectangular pillow is one of the rare cases in which the incorrect but easy procedure sometimes approaches a correct result.

Index Painting
Editing palette indexes instead of pixel colors; it implies caring about palette organization (two palettes with the same colors in a different order are different) and not only about limiting the available colors.

Deliberate attention for building the final image through an explicit indirect mapping mechanism can have a variety of benefits and purposes, mostly related to determining actual colors after editing the image:
  • Making images that can be displayed with different but "parallel" palettes (as typical of many videogames with recolored sprites, which can be implemented with a simple palette swap).
  • Distinguishing palette indexes in order to treat identical colors as logically different, for example because they are shades in different color ramps.
  • Caring about the use of palette entries rather than their actual color (e.g. "I need three entries for flesh, eyes and pupils and I'll reuse hair colors for irises" vs. "I need three entries for rosy pink, blueish white and pure black"); palette structure can be more important and more stable than the contained colors.
  • Controlling palette indices exactly (as opposed to letting the paint program manage them automatically) because they also have some conventional meaning: transparency (e.g. index 0 is transparent), metadata about a game sprite such as whether a pixel is a solid part of an object, special display-time palette tricks (e.g. indexes in a certain range are subject to color cycling) and so on.
  • Allowing use of tools, like semi-transparent brushes, compositing transparent layers, blurring, etc. that are fundamentally unsuitable for simple palette-based image representations. For example, editing a high bit depth greyscale image and mapping grey ranges to palette colors, as popularized by Dan Fessler (1,2).

1. http://www.danfessler.com/blog/pixel-purism-process-vs-results
2. http://www.danfessler.com/blog/hd-index-painting-in-photoshop



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Re: Pixels And Art Glossary (v.0.5)

Reply #71 on: March 05, 2016, 02:28:36 pm
There is already a short entry for Indexed Image/Color.

Personally, I never gave Index Painting much explicit thought because in all pixel art tools I've used (starting with PaintMagic on the C64 and DPaintIII on the Amiga500), "Index Painting" (though it was not called that back then I think, it didn't seem to have a name then) was just the default or only mode the tools and hardware(like the C64) could even handle, so to me, that was always the natural way to go/think about pixel art.

With non-indexed modes around today however, "Index Painting"(what making Pixel Art really already always was imo) should indeed be mentioned separately, but I suggest in more than just one additional entry, broken down into more specific terms:

Index Painting (broad generalization goes into that with links to Dan's articles)

Pallete Swap (full and partial swaps, with examples like faction colors in strategy games or a number of "identical" grayscales for different elements like clothes for individual partial swaps per element)

Color Cycling (a special case of a number of "Pallete Effects")

Palette Structure (logical mapping between palette indices and objects those indices will be used for (skin colors, shoe colors, ... closely related to preparing something for effects like Color Cycling and partial or full Palette Swaps)

Pallete Effects (umbrella term for things like Color Cycling, Palette Swaps, Palette Fading)

The fact, that using automated tools ( "dirty" as they're often called) which cause mutations of affected pixels by color without caring about indices, are mostly unsuitable if Palette Structure is important for programmatic effects seems obvious but maybe it should be mentioned in an entry about "'Dirty' Tools" without condemning them as forbidden though, just to point out that their usage can require manual cleanup and making sure each pixel refers to the correct palette index after applying them (seems though that this might be better covered in a tutorial about Palette Structure as it's pretty longwinding for a brief description which aims to be free of judgement).

...

Added example and fleshed out description to the existing Pillow Shading entry:

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Re: Pixels And Art Glossary (v.0.5)

Reply #72 on: March 07, 2016, 05:30:42 pm
Added entries for Palette Effect, Palette Structure and Palette Swap.

---

Palette Effect
In Indexed Images/Modes where each pixel in the image refers to a specific color in a sequence of colors(=palette) (instead of holding the full definition of the color in each individual pixel itself), a number of visual effects such as Color Cycling and Color Fading can be achieved by manipulating the palette instead of manipulating the pixels themselves.

This was used a lot on old hardware as manipulating the definition of colors in the palette took much fewer CPU cycles than going through the image and changing the actual pixels themselves.

A simple example for a Palette Effect is just re-defining a color in the palette:
If a thousand pixels in an image referred to color at index five in the palette and index five would hold Green and index twelve would hold Red, all thousand pixels could be changed to Red by changing the color at index five from Green to Red instead of going through the image and looking for every Green pixel and changing the pixel itself to refer to index twelve.


Palette Structure



Palette Swap

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Re: Pixels And Art Glossary (v.0.5)

Reply #73 on: March 09, 2016, 06:36:55 pm
Added History Of Pixel Art, Index Painting and Color Cycling.


History Of Pixel Art
see The History Of Pixel Art


Index Painting
Creating Pixel Art in Indexed Modes, working with Indexed Images while paying attention to Palette Structure and keeping possible Palette Effects in mind and at all times keeping control over (if necessary by fixing the results) the pixel level polish of a piece even when using tools that influence more than one pixel at a time.

Historically, "Index Painting" is the natural way to go and think about making Pixel Art as most hardware and digital image editing tools either used Indexed Modes as the default mode or simply did not provide any other modes. The term "Index Painting" was not around then because there simply was nothing else. Today the term seems to be used to set "Pixel Art"(in the sense of Index Painting) apart from other "Pixel Art"(in the sense of Digital Painting and Computer Generated Imagery(e.g. 3D renderings)) and the third kind of "Pixel Art"(the purists "one pixel at a time"- process).

Some advocate placing one pixel at a time as the only "allowed" process to create "Pixel Art"(a term which eludes definition itself) while others advocate whether something is or is not "Pixel Art" can not be defined by processes but only by looking at the results.

The actual term "Index Painting" emerged from the on-going online debate about "pixel purism", processes and results:
http://www.danfessler.com/blog/pixel-purism-process-vs-results
http://www.danfessler.com/blog/hd-index-painting-in-photoshop


Palette Swap - Color Cycling

further reading:
https://en.wikipedia.org/wiki/Color_cycling

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Re: Pixels And Art Glossary

Reply #74 on: March 13, 2016, 08:35:29 pm
Updated entries for Construction and Dithering & Dither-AA (and removed version number as the board already shows when a post was last edited).


Construction

further reading:
https://en.wikipedia.org/wiki/Drawing#Form_and_proportion
https://www.google.com/?q=drawing+fundamentals+construction


Dithering & Dither-AA

further reading:
https://en.wikipedia.org/wiki/Dither
https://en.wikipedia.org/wiki/Dither#Digital_photography_and_image_processing

Offline Ai

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Re: Pixels And Art Glossary

Reply #75 on: March 15, 2016, 02:53:05 am

Construction

further reading:
https://en.wikipedia.org/wiki/Drawing#Form_and_proportion
https://www.google.com/?q=drawing+fundamentals+construction
Reminds me of thumbnailing, which is sort of proto-composition, proto-construction and proto-gesture all rolled together. Which makes me think of the fact that gesture typically refers to the posture of an animate creature, but can usefully be applied to any organic object (and arguably many non-organic ones, or even the picture as a whole.).. and wonder if you are going to point out in the gesture entry that gesture is not restricted to animate things.
AA tutorial about handling irregular lines.

If you're not at least a little uncomfortable, chances are you're not learning that much.

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Re: Pixels And Art Glossary

Reply #76 on: March 15, 2016, 11:43:25 am
Reminds me of thumbnailing, which is sort of proto-composition, proto-construction and proto-gesture all rolled together. Which makes me think of the fact that gesture typically refers to the posture of an animate creature, but can usefully be applied to any organic object (and arguably many non-organic ones, or even the picture as a whole.).. and wonder if you are going to point out in the gesture entry that gesture is not restricted to animate things.
Yeah, Gesture really works for anything organic or not. I think the specific term Gesture however came from figure drawing, living creatures and animation so it should refer to that even if it is related to the "other" use. Not sure what the other use is called though: Maybe Rhythm & Flow = Gesture for everything which is not a living being?

I thought Thumbnailing is the same as sketching/doodling but on a very small scale to figure out composition/partitioning/placement/etc. quickly and to make lots of iterations fast without having to worry about the details that go into creating a polished artwork from it.

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Re: Pixels And Art Glossary

Reply #77 on: March 15, 2016, 01:33:07 pm
I thought Thumbnailing is the same as sketching/doodling but on a very small scale to figure out composition/partitioning/placement/etc.
I guess so. My experience of thumbnailing is that you can put anything that reads and conveys a quick useful impression (in a 1"..2" picture size) in them. Gesture of the focal figure(s) might be included - IME it's usually central.
AA tutorial about handling irregular lines.

If you're not at least a little uncomfortable, chances are you're not learning that much.

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Re: Pixels And Art Glossary

Reply #78 on: March 18, 2016, 06:59:17 pm
Value & Key

see also Brightness, Lightness & Value