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Posted on 22/09/07 10:50:38 PM |
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Steve Cain
* Posts: 18 Reply |
Vector graphics in Photoshop
I have been using Photoshop for several years now but there has been something I have never found out how to do. Photoshop is supposed to be able to create vector based shapes and type, but how? If I create a Type layer it is raster based, same with any shapes. Zoom in on a Type layer and you quickly see the pixels. How can I create a vector based type, or shape, layer? Thanks. |
Posted on 23/09/07 10:06:06 AM |
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Bob
Expert Expressionist Posts: 130 Reply  |
Re: Vector graphics in Photoshop
Type layers are vector based and so are shape layers. And, you can create custom vector shapes using the pen tool. Those pixels that you see when you zoom in are not a sign that the type is raster based. The vectors that define the shape of the object are mathematical formulae. For the object to be visible, pixels must be created and drawn on the discrete pixel based representation of the layer. You can only get an approximation of the true mathematical shape so you will get jaggies. In addition, if you have specified antialiasing, you will get additional variation in the boundaries due to that. This is a rasterization process, but that doesn't make the text and shape layers raster based. If you scale up the vector based text, the boundaries are re-rastorized at the new size. Your text retains it's definition and quality. A raster based object would simply resample the existing pixels and the boundaries would become less defined and poorer quality as it is scaled up. |
Posted on 23/09/07 10:28:28 AM |
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Bob
Expert Expressionist Posts: 130 Reply |
Re: Vector graphics in Photoshop
I was just thinking, a demo may be helpful. In the following image, there are three lines of text. All three lines started out as copies of the same vector based text. The first line is the original vector based text. The second line is the vector based text scaled to a larger size. The third line is the original vector text first converted to raster based and then scaled to the same size as the second line.  |
Posted on 23/09/07 11:00:07 AM |
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Steve Cain
* Posts: 18 Reply |
Re: Vector graphics in Photoshop
Hi Bob, I understand how vector graphics are created and how they are rendered when scaled up. If I create text in Illustrator I can enlarge as much as I like and, as the text is vector based, the text edges remain smooth irrespective of how big it is. In Photoshop, if I zoom in then the pixels just become bigger. It is a rasterised layer. My questions are: Why is the text in Photoshop showing as bit mapped? Is it really bit mapped or is it vector but just being shown as a bit map? I have read many books on Photoshop which all mention the Vector text in Photoshop but none explain how to create it. I have read many articles on the Adobe website. Posted questions on this on the Adobe forums, but never got an answer. The help section in Photoshop explains perfectly the difference between bit mapped and vector graphics, but not how to create them. At the moment I have to create text in Illustrator, save it out and open with Photoshop. If I need a bigger version I have to go back to Illustrator, scale up the text, save it out and open again in Photoshop. |
Posted on 23/09/07 12:39:32 PM |
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Deborah Morley
Makeover Magician Posts: 1319 Reply  |
Re: Vector graphics in Photoshop
Hello Steve, I am not an expert on this but an old photoshop manual says: Type consists of mathematically defined shapes...when you add type to an image, the characters are composed of pixels and have the same resolution as the image file-zooming in on characters shows jagged edges. However, photoshop preserve the vector-based outlines and use them when you scale or resize type, save a PDF or EPS file or print to a PostScript printer. I have found if the resolution is only 72dpi you can end up with pixellated type, if it is 180dpi or over it is fine. Hope this helps |
Posted on 23/09/07 2:53:23 PM |
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Steve Cain
* Posts: 18 Reply |
Re: Vector graphics in Photoshop
Hi Deborah, The picture (sorry, pun not intended) I am getting here is that Photoshop displays a raster (bit mappped) image on the computer screen and that a vector graphic cannot be displayed in that image. Certainly when printing out at different sizes the image is always smooth, so Photoshop is definitely outputting vector images to a printer. If I then open up a Photoshop created PSD document containing text layers in Illustrator, I get the option to "Convert Photoshop layers to objects". This then will scale up to infinity with smooth edges (vector text). At the moment I am not outputting to a printer. I have created vector based text (with added styles) in Illustrator which I use for web applications (raster images). But if I need a larger text layer for a bigger web graphic I cannot use Photoshop to enlarge it. I have to go back to Illustrator, scale up and then save out as an .ai file and open up in Photoshop. Then I have a larger version to work with. One day it will all become clear. Cheers, Steve |
Posted on 23/09/07 8:44:10 PM |
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Bob
Expert Expressionist Posts: 130 Reply |
Re: Vector graphics in Photoshop
Steve, Photoshop is a raster based program. So, yes, it has to display a raster based image. However, the vectors are preserved in vector based objects. You should be able to scale the text in Photoshop and get the same quality. You shouldn't have to go back into Illustrator to scale it. Have you tried exporting the Illustrater image to PDF instead of saving out in .ai format? See this: http://kb.adobe.com/selfservice/viewContent.do?externalId=317612&sliceId=2 |
Posted on 23/09/07 11:03:33 PM |
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Steve Cain
* Posts: 18 Reply |
Re: Vector graphics in Photoshop
Hi Bob, I tried Exporting from Illustrator as a psd and also saving as a pdf. Opening both in Photoshop produced raster images. I am beginning to realise now that any document open in Photoshop (whatever the format) will always appear as a raster image. I will play around with the various options in the Adobe link you gave and see what the results are. I guess I just need to understand the basics a little more. Thanks for your help. Steve |
Posted on 24/09/07 01:07:15 AM |
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dave.cox
Marquee Master Posts: 518 Reply  |
Re: Vector graphics in Photoshop
Hello Steve. Yes Photoshop does support vectors shapes, and type. If you zoom in, you will see the pixels that photoshop is painting on the screen, but if you enlarge the text and zoom in, you will see that the enlarged text has been filled in with many more pixels, as compared with an enlarged rasterized image of the same text. When you create text or an object with one of the shape tools, you will notice that the object is created with a path, much as it is in Illustrator. You can also fill or stroke the path much as you can in illustrator, and even scale it the same. When you rasterize the object, it is no longer a vector image, but becomes a pixel image. |