What does it means to vectorize an art?

[suken19]

Hi everyone. I have two questions. A) When someone ask you to vectorize an art, let say a tree, what do they mean and how are we suppose to do that? Secondly, is it possible to make an image into 300 dpi? I know that the higher the dpi, the better quality the picture will be. But what exactly is dpi and how are we suppose to apply the 300 dpi into that image?

Thanks for any help.

[urstwile]

It would be helpful if you could post an example of an image you'd like to "vectorize".

Vector is a type of way of producing an image, however, it's not appropriate for the majority of photographic (also known as raster) images. The advantages to doing something as a vector graphic is that the image is scalable up and down without any loss in quality. However, depending on the level of detail in the image, as well as the desire to maintain a photographic appearance, it may not be the appropriate choice.

Logos are generally vector, photos are raster.

In terms of your second question, you can't just make an image 300 dpi unless you start off with something higher than that. So if your image is 72 dpi to begin with, simply changing the dpi to 300 will not work. You'll lose a significant amount of detail and end up with jaggies. The best thing is to start with a high resolution image.

I hope that helps.

[Ned]

Hi everyone. I have two questions. A) When someone ask you to vectorize an art, let say a tree, what do they mean and how are we suppose to do that? Secondly, is it possible to make an image into 300 dpi? I know that the higher the dpi, the better quality the picture will be. But what exactly is dpi and how are we suppose to apply the 300 dpi into that image?

Thanks for any help.
Okay, let me try to answer this...

First of all, there are two types of image types, Raster (also known as Bitmap), and Vector. Raster images are created by taking a whole bunch of little "dots" (or square pixels, diamonds, elipses, etc.), each with a different color. You have so many of these dots in each square inch, in order to create your image. Obviously, the more different colored dots you have in each of those square inches, the better the definition, and the higher the quality of the image. That is what we call "resolution". Raster/bitmapped images are "Resolution Dependent", because you need more dots, and more file information, to make a better quality and/or a larger picture. Your computer monitor (as well as non- high def. TV) displays at 72ppi (pixels per inch), whereas print requires approx. 300dpi (dots per inch) to make a quality print on regular paperstock at a normal viewing distance for readable product. The formula is that you require 1.5 to 2 times the resolution as the screen frequency of the printer (measured in lines per inch, lpi, and ranges from 80lpi for newsprint, to 133lpi for coated magazine paper).

Vector art, on the other hand, is a process of creating artwork defined by "paths", in a vector creation program like Illustrator, Freehand, or Corel Draw. Vector art is created by the computer using mathematical equations, with one point defined, then the direction, distance, and strength of curvature to the next point defined by "bezier handles".
Vector art is "Resolution Independent", meaning that the same vector art can be scaled to any size, from a tiny classifieds logo to a large billboard sign, and all the lines will retain the same crispness and sharpness of edges, as the mathematical equations behind the creation remain the same. Also, vector art can be used for all kinds of printing besides paper. Screen printers and vinyl plotters/cutters (for signs, vehicle graphics, etc.) often require vector files to work with.

As far as "When someone ask you to vectorize an art", you need to wait until you learn how to use Illustrator, Freehand, or Corel Draw, and how to draw using the pen tool.

*EDIT: I forgot to answer your second question, but Urstwile covered it...

[suken19]

Thanks for the help so far. So how are we suppost to vectorize a logo? Do we just use the pen tool and go around the logo making that path form? Or their is a way to vectorize right away?

BTW, I do know how to use Illustrator but just a little bit confuse about vectorizing.

Thanks

[seamas]

The best way to make something in a vector format is to trace it with the pen tool.

There is a"live trace" function on Illustrator CS2 (and some earlier variations on the automatic trace on earlier versions of Illy).

However, mnost users find that the Live Trace function isn't as precise as one would wish, and creates way too many pen points. This makes later adjustments and tweeking difficult.


Learn to use the pen toll, it really is one of the most important tools in Illustrator.

[Ned]

There is a"live trace" function on Illustrator CS2 (and some earlier variations on the automatic trace on earlier versions of Illy).

There was no previous automatic tracing in Illy. It was in a seperate engine called "Adobe Streamline". Or Photoshop will also do essentially the same thing (make path from selection).

Of course, actual proper usage of these tools are rare and far-between.

Note: Streamline is no longer available from Adobe, so unless you can come across an old version of the program, you need to upgrade to CS2 or CS3, if you want this functionality (if you can call it that).

[hewligan]

There was an autotrace tool in previous versions of Illy. It would only trace a single object, though, while Livetrace will create multiple objects. It wasn't very useful.

[seamas]

There was an autotrace tool in previous versions of Illy. It would only trace a single object, though, while Livetrace will create multiple objects. It wasn't very useful.

Yes, this is the feature I was referencing.