Instead of equipping every workstation with enough RAM and CPU power to render pages at 200x200 dpi (not to speak about the disk sizes and network throughput one needs to store and transfer the resulting documents), it was enough to have one $10,000 laser printer to do the job for the complete department. Industrial printing machines used by publishers were already able to cope with much higher resolutions.īy delegating the computational intensive part to use-time, that is, the printing device, PS provided portability between all these devices and made it possible to prepare high-quality documents even on affordable computers. However, even at that time, a laser printer was able to print a page with 200x200 dpi or more. Going higher (300x300 or 600圆00 dpi) was basically impossible. Rendering a complete A4 page at 150x150 dpi resolution on such a system was already challenging. In the 80s a decent workstation (VAX-11) was able to compute 1.5 million instructions per second (MIPS) and was equipped with maybe 1 MiB of RAM.In PDF, all calculations have be completed when the PDF file is produced.Īt its time, the PS model had some clear advantages:.PS is a (Turing-)complete language that permits to defer arbitrary computations to rendering time, that is, when the PS file is used (i.e., printed).There is a great Q&A that discusses the fundamental differences between Postscript (PS) and PDF from a technical perspective:įundamental differences : PSTricks, TikZ/PGF and others, but misses a bit on the (historical) significance of these technical differences:īasically, the technical differences are: Updating the existing tool chains to PDF would require a massive investment. Postscript has been a long-lasting and broadly accepted standard. With PDF such a tweak is much more complicated.įrom a publishers perspective, I think, the only fundamental reason is legacy software. With Postscript, doubling the line width in the whole document is easily accomplished by putting userdict /setlinewidth put If, for instance, line art in a document is too faint, the publisher may want to enhance it a bit globally before giving the document to press. One feature that makes Postscript the preferred format, in particular for a publisher, is its editability. And if you have a Postscript printer, it can do these computations for you. It can even solve differential equations. The Postscript based PSTricks package is an example that heavily makes use of graphical computation. PDF shows just the result (after some conversions, sometimes called "Distillation") of the computation Postscript is able to do. Both are free.Postscript is still used as an intermediate document format, since it is a fully fledged programming language allowing you to compute graphics, which PDF doesn't. I highly recommend SumatraPDF or MuPDF if you're after something a bit more. You may or may not need an add-on or extension to do it, but it's pretty handy to have one open automatically when you click a PDF link online. Most web browsers, like both Chrome and Firefox, can open PDFs themselves. It's completely fine to use, but I find it to be a somewhat bloated program with lots of features that you may never need or want to use. Adobe created the PDF standard and its program is certainly the most popular free PDF reader out there. Most people head right to Adobe Acrobat Reader when they need to open a PDF. PDF files always look identical on any device or operating system. The reason PDF is so widely popular is that it can preserve original document formatting. The Portable Document Format (PDF) is a universal file format that comprises characteristics of both text documents and graphic images which makes it one of the most commonly used file types today. Most often, the conversion is to JPEG, which offers lossy compression, or PNG, which offers lossless compression. To overcome this, PSD is often converted to a file format that can compress the data. A free alternative to Adobe products is the GNU Image Manipulation Program, otherwise known as GIMP.ĭue to the size of PSD files, they are not easy to transport, store, or share. How to open a PSD file?Īdobe Photoshop is the most common program to open a PSD file. One drawback of PSD is that it can be large and unwieldy. PSD can store an image along with a complex array of its corresponding layers, vector paths, objects, filters, and more, all in one file! PSD allows a user to make surgical edits on individual components of an image or a graphic design while retaining the file’s information in an accessible format. Photoshop Document (PSD) is the default file type for Adobe Photoshop, a powerful and complex graphic design program.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |