Talk:Vector graphics

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Contents 1 Scaling Illustration 2 Terms: Vector Graphics vs. Geometric Modeling 3 image! 4 path 5 How the "brain" and "eye" work? 6 Programs Related 7 Punctuation 8 External links 9 Example photos 10 More than one vector graphic example 11 Vector display 12 What was wrong with the original camera example? 13 What's wrong?

[edit] Scaling Illustration

Added an illustration showing the effect of scaling on vector and bitmap images; this illustration demonstrates a key advantage of vector-based graphics (the ability to scale them to any size without degradation).

Agateller 06:21, 13 January 2006 (UTC)

[edit] Terms: Vector Graphics vs. Geometric Modeling

Please see my comments under the "raster graphics" page.

Presenting "raster graphics" and "vector graphics" as two alternative ways of doing 2D computer graphics made sense in the '70s, but that view is no longer valid or useful today. They are not alternative ways but succesive stages of 2D computer graphics.

What this page calls "vector graphics" is better called (2D) "geometric modeling", and what it means by "raster graphics" are nowadays called "digital images" (as mathematical objects) or "frame buffers" (as concrete data structures). Rendering a geometric model produces a digital image, and virtually all output devices today can only print/display digital images. (In fact, I believe that even large format plotters have been largely replaced by raster-based devices -- essentially wide-bodied printers, using inkjet, electrostatic, or laser technology).

Changing the name "vector graphics" to "geometric modeling" would also allow us to unify the 2D and 3D geometric modeling pages. After all, the basic idea is the same, and many primitives (polygons, splines, etc.) are the same.

Moreover, it seems that many traditional applications of 2D graphics, such as commercial artwork, are being taken over by 3D graphics -- which provide effects like shadows and shading. At the very least, the boundary between 2D and 3D graphics seems to be getting blurred.

Rendering is still often called "rasterizing" , both because of the original vector/raster nomenclature, and because the first algorithms did it in real time, by sweeping the "vector" representation with a horizontal line in sync with the CRT electron bean path ("raster"). That solution was imposed by the lack of a frame buffer. Presently, however, scanline-sweep is only one among many methods for converting the geometric description into an image. For instance, the popular Z-buffer method generates the pixels in random order. Thus "rasterizing", while still in wide use, is a rather old-fashioned word.

Recently I wrote Portable_Document_Format#Layers. I wonder how this would translate into your terminology.--Patrick 12:45, 5 Mar 2004 (UTC)

Well, what about this:

---

A PDF file often combines geometric primitives, text, and digital images. E.g., the general reference map of the US [1] uses:

• polylines or splines for coastlines, administrative boundaries, rivers, highways;
• polygons or circles for lakes, cities, and Interstate highway symbols;
• text for labels;
• digital images for mountain relief.

In the Postscript/PDF imaging model, these graphic primitives are sequentially painted on a "virtual canvas", in the order in which they occur in the file; so one can have arbitrarily many layers of text, geometric shapes, and images, interleaved in any order. Images can also be clipped to a boundary of arbitrary shape.

In zooming in, the outlines of geometric primitives and text remain sharp and smooth; whereas image data breaks up into separate pixels, rendered as uniformly colored rectangles. An example of a PDF map done entirely with geometric primitives is [2]. In map [3], the colors are provided by a single background image, while coastlines are represented as polylines; the mismatch between the two layers is noticeable when the map is highly zoomed in.

---

The PDF page still has plenty of room for improvement. The Postscript language and its imaging model certainly deserve a separate page and a better description, and part of this information belongs there. Also, for instance, images are not merely plopped down on to the canvas, but can be dithered according to a "dithering screen" -- which may be either the printer's default or a client-provided one. The Postscript model also allowed one to treat each pixel as a geometric object, and (e.g.) paint each pixel as a tiny hexagon rathr than a square. I don't know how much of that freedom is retained in the PDF model. I am not sure, but I bellieve that Postscript also could perform smooth interpolation of a given image; in that case your remark about zoomingin, above, would have to be qualified. Jorge Stolfi 21:38, 5 Mar 2004 (UTC)

[edit] image!

Someone make a vector equivalent of this:

Show that it still holds the same shape at larger sizes, and somehow demonstrate the presence of discrete objects instead of pixels. - Omegatron 00:39, Apr 5, 2005 (UTC)

Why do you want this done? --InvaderJim42 00:58, 12 August 2005 (UTC)

Omegatron, judging by your user page. I'm completely convinced that this is something you're capable of doing yourself. So, what's this about? Whether you've posted this comment rhetorically or not, your point is impenetrable either way. 198.49.180.40 21:13, 24 July 2006 (UTC)

I agree more examples like this one should be used. Making vector graphics out of photos is mostly pretty useless (it isn't done in Wikipedia for example), but for smilies, arrows, flags and stuff like that, it's very useful (and this is done in Wikipedia). Cristan 15:47, 20 October 2006 (UTC)

Useless? See the caption on the photo. Oicumayberight 17:31, 20 October 2006 (UTC)

How's this? Althepal 07:29, 7 March 2007 (UTC)

[edit] path

[edit] How the "brain" and "eye" work?

The second paragraph relates vector/bitmap graphics to the way a human "brain" or "eye" works. Is there any source for this information? It certainly seems intriguing but I wonder exactly how much solid research it's based on. Especially when it refers to ""recent studies," which I don't see any link to.--Eraboin 03:52, 4 February 2006 (UTC)

I looked around on Google a bit, and found this, which may or may not be of help to you: http://scholar.google.com/url?sa=U&q=http://www.kyb.mpg.de/publications/pdfs/pdf741.pdf 'Does the brain know the physics of specular reflection? A Blake, H Buelthoff - Nature, 1990' Homtail 21:49, 9 July 2006 (UTC)

The eye works around the rod and cone system, so that could be considered roughly equivalent to a raster image. The brain percieves things differently--it tends to take in the entire scene, grouping things together and processing images that way. If you see a 9x9 grid of black dots where the rows are spaced farther apart than the columns, you tend to think "three columns" rather than "nine dots." Also, seeing six dots form a triangle makes you think "triangle" before "six dots." There are several different concepts like that, and these kinds of things make up the psychological study of perception. I'm sorry I can't cite any handy sources; I just have what stuck with me after Intro to Psychology. 129.61.46.16 20:10, 18 July 2006 (UTC)

I have removed this section from the article, since it appears no citations are forthcoming. Wikipedia's verifiability policy prohibits us making claims which are neither supported by citations nor easily verifiable by non-specialist readers.

The text I have removed is as follows:

The human eye works as a bitmap picture: it catches the image in a mosaic raster of photon recipient nerves, a pixel image. But the brain — according to recent studies^{[citation needed]} — handles it as a vector image. Perhaps because — like in computers — this is easier to store. It explains why humans can recognize simple drawings like cartoons with just outlines because this is so close to what the human brain makes of the visual world anyway. It also serves as an explanation for the fact that logos and signs with easy and geometric shapes are more easily remembered and recognized.^{[citation needed]}

Naturally it could be restored to the article if citations are provided for these claims. I would note that should this occur, it should be placed in a subsection, not put back in the article introduction, which is supposed to be a basic overview of the article's subject, not a dumping ground for tangential issues (the nature of human vision is not a fundamental aspect of the nature of vector graphics). — Haeleth Talk 10:09, 17 August 2006 (UTC)

[edit] Programs Related

Rotoshop is the program used to create A_Scanner_Darkly_(film)#Animation. It uses a combination of rotoscope with vector graphics.

[edit] Punctuation

I think replacing hyphens with dashes in the second paragraph would be fair.
Vadik wiki 00:19, 14 March 2006 (UTC)

"Vector graphicsaaaa" Is the "aaaa" bit on purpose ? Kristian Joensen 21:26, 2 July 2006 (UTC)

also theres some graffiti or somthing like that on the intro, i was going to fix it but i dont know what words went there

Fixed. You can retrieve what was once there from the page history. Oicumayberight 03:59, 24 March 2007 (UTC)

[edit] External links

I have removed the external links section. Originally I had intended merely to clean it up by removing the spammier links, but when I looked more closely, I discovered that it contained only three types of link:

1. Advertising for commercial software (AmanithVG, Raster-To-Vector)
2. Links to sites providing "free" vector graphics files
3. Links to open-source programs and libraries that handle vector graphics (Inkscape, Cairo)

(1) is classic linkspam, to be scourged with fire wherever encountered. (2) is less offensive, but still advertising; this is an encyclopedia, not a link directory, and our mission in this article is to help people understand vector graphics as such, not to help people find free clipart. (3) then falls to the same issue. Moreover, the internal links to pages like List of vector graphics editors already provide better and more complete information about what software is available to edit vector graphics; it is useless to duplicate this effort badly with an incomplete set of external links.

Since therefore none of the links in the article actually fall into the scope for external links defined in our guidelines, I think we are better off without the section. It can be recreated easily enough if anybody finds a link that is actually appropriate for inclusion. — Haeleth Talk 16:21, 17 August 2006 (UTC)

[edit] Example photos

I think both examples should remain. Readers should know that vector graphics are useful for more than information graphics. Oicumayberight 01:01, 19 October 2006 (UTC)

The camera diagram and the hand/tool picture are clearly useful, but I'm not convinced of the usefulness of the train example. In my experience pictures like that are normally produced by an illustrator drawing them from scratch, probably using raster graphics anyway, so vector graphics will (normally) not be involved. As for reducing bandwidth, note that the vectorised version is actually 1 kb larger in this case. Bandwidth reduction is normally accomplished using JPEG compression, not by converting photos to vectors.

Your experience is not the norm. Most modern illustrations for computer graphics are not from scratch, especially when realistic proportions are the goal. Adobe illustrator is the most popular vector graphic editing program. It allows vector tracing of photos either manually or automatically. The file size of the photo used in the caption is not relevant to the point about file sizes mentioned in the caption. That photo is a bit-mapped version of a vector file. The actual vector file would be much smaller, most-likely by a factor of 10. I don't have the original file. But anyone who uses vector graphics would tell you that this is the case. Oicumayberight 23:56, 20 October 2006 (UTC)

Personally I'd prefer to see it replaced with a real-world example of vector graphics -- perhaps a screenshot of an iconic game like Asteroids or something. Or with an example of the kind of thing that is nearly always done with vectors rather than pixels, like a map. But I won't change anything unilaterally. :) — Haeleth Talk 22:42, 20 October 2006 (UTC)

Asteroids? That was an example of vector graphics 30 years ago. There are plenty of examples of more complex uses of vector graphics today. Since wikipedia only displays bitmap graphics, a PDF file would need to be attached. The problem I have is with this whole premise that vector graphics are the exception and yet they are being used more and more since the advent of Macromedia Flash and Adobe PDFs. Vector graphics are used for aesthetic art much more than what is shown in the examples. Oicumayberight 23:56, 20 October 2006 (UTC)

[edit] More than one vector graphic example

This page IS about vector graphics, right? Then, should there not be more than one ACTUAL vector graphic on it? 84.70.112.198 17:31, 31 December 2006 (UTC)

SVG is the only vector graphic format that can be displayed in wikipedia. There only needs to be one example of a vector graphic per format. Unless you are looking for downloadable links or links on external HTML pages, the other vector formats (PDF, EPS, Flash, WMF, DXF, X3D, etc) cannot be displayed without converting them to a bitmap on this page. Oicumayberight 22:01, 31 December 2006 (UTC)

[edit] Vector display

Vector display redirects here, but unless I'm much mistaken, nothing on this page discusses vector displays. What's with that? Rawling4851 00:14, 22 January 2007 (UTC)

All modern current computer video displays translate vector representations of an image to a raster format. The raster image, containing a value for every pixel on the screen, is stored in memory. Starting in the earliest days of computing in the 1950s and into the 1980s, a different type of display, the vector graphics system, was used. In these systems the electron beam of the CRT display monitor was steered directly to trace out the shapes required, line segment by line segment, with the rest of the screen remaining black. This process was repeated many times a second to achieve a flicker-free or near flicker-free picture. These systems allowed very high-resolution line art and moving images to be displayed without the (for that time) unthinkably huge amounts of memory that an equivalent-resolution raster system would have needed. These vector-based monitors were also known as X-Y displays.

One of the first uses of vector graphic displays was the US SAGE air defense system. Vector graphics systems were only retired from U.S. en route air traffic control in 1999, and are likely still in use in military and specialized systems. Vector graphics were also used on the TX-2 at the MIT Lincoln Laboratory by computer graphics pioneer Ivan Sutherland to run his program Sketchpad in 1963.

Subsequent vector graphics systems include Digital's GT40 [1]. There was a home gaming system that used vector graphics called Vectrex as well as various arcade games like Asteroids and Space Wars. The Tektronix 4014 also deserves a mention even though the display was static.

What were you expecting besides this? Oicumayberight 01:26, 22 January 2007 (UTC)

... ok, shoot me. How dumb do I feel right now? Rawling4851 10:58, 22 January 2007 (UTC)

[edit] What was wrong with the original camera example?

I thought the original camera example showed a better contrast of pixelation than the bottle.

The bottle only shows a good contrast of the difference when the user looks at the larger version. The thumbnail is only "7x magnified" at the full 1000 × 1125 pixel size. If nobody bothers to click and enlarge the image, the point gets lost. Oicumayberight 03:33, 7 March 2007 (UTC)

Okay, I can make it more obvious smaller - soon. But the pixelation is still very obvious even as a thumbnail. The reason for the replacement is two-fold: One, the example with the camera is in jpeg, and that is not a good format for this type of picture. Two, the camera picture is fair use, and should not be used when there is a free alternative. Althepal 05:08, 7 March 2007 (UTC)

Understood. Oicumayberight 05:10, 7 March 2007 (UTC)

Suggestion. It would be more obvious with angular part of the bottle than the straight horizontal or vertical lines. There just isn't much close up detail in the bottle. Maybe us the bottle cap. Oicumayberight 05:13, 7 March 2007 (UTC)

I replaced the file with a smaller one, showing more magnification, and added text for detail. Althepal 05:29, 7 March 2007 (UTC)

Let me know if you think the magnification is too high, and if the sample area is too small, to show the raster up-sizing. Althepal 05:32, 7 March 2007 (UTC)

Looks good. Get's the point across. Oicumayberight 07:46, 7 March 2007 (UTC)

[edit] What's wrong?

How come Wikipedia has so many problems with vector graphics? When downsized, they are not as smooth as pngs. In some pictures, the elements don't show up when a certain size. I've also noticed that Hebrew letters don't show up unless converted to path. Althepal 20:53, 9 March 2007 (UTC)