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Help understanding Vector Graphics

What are they? How do you create them? (in Adobe and CorelDraw graphic suites) Can a photo be saved as a Vector graphic? Thanks group. jt_stuber

zachninme6 years ago
And no, you can't make them from photos. Vector graphics are best for blocks of color... like logos.
Alathald6 years ago
While I know nothing of the Adobe suite, there is some great open-source vector graphics software called Inkscape. If you've never tried vector graphics, it's pretty easy to learn and, depending on what you're drawing (say, a cartoon or similar line art), it is IMO much easier to use than rasters. The way drawing with vectors works is by drawing a line from one point to another, then 'curving' that line with a vector. The vector tells the line what direction, and how much, to curve. A bit like playing that game of old call tanks (I think thats what it's called...). There are a lot of examples of vector images on the web, simply do a search for .SVG files (Scalable Vector Graphics files). If you're running Firefox, you can even view them without downloading it (I think Opera and Safari also support .SVG but I'm not sure about Internet Explorer). Have fun with vectors, they are much more flexible than rasters!
jtobako7 years ago
from what i understand, vector graphics are "go this far and put a point, conect it to this point along this curve" (dfx,gif? and tif? files?) where 'this far' is defined by how big the pic is. 'normal' graphics are a grid where each location is defined as a specific color. the real difference is when you start changing the size of the picture. when a 'normal' pic has it's size changed, the computer has to guess what the new grid looks like, trying to make, say, 8 pixels do the work of 4 or 16 resulting in the breakup of lines and such (pixelation of the image). vector graphics don't degrade when you change the size of the pic because the computer always calculates the position of all the points, so no mater how much you expand the pic, the computer never has to guess and so the image doesn't pixelate. i don't know the software, but since every point or line has to be an equation, it takes some work to do (beizer curves and such). the tutorials that i have seen transfer photos by hand into vector graphics but there may very well be shortcuts-like i said, i don't know the software.
Essentially, your understanding that vector drawings are defined by their points including their lines and relative properties of included elements. The .dfx is a vector-based format from AutoDesk, but .tif and .gif are both pixel/grid-based. Illustrator has LiveTrace which is one way of an automatic 'conversion' from groups of similar pixels to vector shapes. This takes out the soft transitions in the photo and makes the 'hard-edge' look. Illustrator has another feature that I am particularly fond of. It is Illustrator's quickest way to generate a photo-realistic image without a photo. Gradient Mesh. You can make a regular shape and then define points within that shape which will connect to the edges, top to bottom, side to side, mesh-like. Then you assign each point their own color properties, and the colors automatically gradate from point to point. I may do an instructable some time using this method just because.
LasVegas7 years ago
You guys are confusing Vector Drawing or Vector Illustrations with Vector Graphics; An entirely different beast! Vector graphics is an image made up entirely of lines between points. Anybody remember the game Asteroids? That was "Vector Graphics." A Vector monitor is much more inexpensive and the hardware to generate the video much simpler than "Rastor Graphics." BTW: Yes. I do realize that jt_stuber did in fact mean Vector Illustrations...
PetervG7 years ago
mever7 years ago
I was asked this same question the other day when someone wanted a logo placed on a background image. They had trouble with the logo looking grainy around the edge of the logo. I found out they had started with a jpeg and cut out the white background in photoshop. The blended area between the logo and the background looked ok until it was on the photo where the leftover white background was more visible, when they cut more away it cut into the logo making it grainy or jagged. I had to tell them that they would need the vector graphic to make it perfect because it has defined points where the graphic begins and ends, a jpeg or gif image blends and flattens all that out. It looks fine until you try to cut out that non-vector image and place it on something different. Your eye doesn't pickup on the imperfections until it has something to contrast it against. To get clean lines, you need to start with the best detail possible and vector graphics have exact defined points. You will never get that exact with a jpeg or gif. I have never heard of software that could save a photo as a vector graphic. Photos don't really have defined lines, there is always blending that makes it look organic and natural. I can think of several reasons to try and accomplish this for the scientific data but the image would look rather poor to the eye.
mever mever7 years ago
okay, i take that back. I spoke to someone and found adobe illustrator can. Its called Live Trace under the object menu. The result is not bad but looks more like a cartoon as far as i can tell. I got an out of memory error trying to use it on my machine. With as much data as this might process and produce from a photo, 2 gig of ram might not be enough for the higher settings. Just wanted to correct myself and let everyone else know.
jt_stuber (author)  fungus amungus7 years ago
thanks
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