Introducing Vector Graphics and Inkscape
Paths and objects can be combined very quickly with boolean operations, such as intersection, union, difference, exclusion and others. Simply select the objects to combine and choose the desired operation from the Path menu. Figures 3 and 4 show what you get when you intersect an oval and a star.
Solid colors can be dull, don't you agree? The fact that vector drawings are generated through computer instructions doesn't mean that their components must all be in solid colors. To create smooth color transitions (that is, gradients) from one side of an object to another, select it and open the Fill and Stroke dialog from the Object menu. That window allows you to apply several gradient types and place the corresponding stops—the exact start and end points between which the color transition must take place. Gradients can be applied to any object, including text.
Inkscape has buttons or menu entries to copy, paste and duplicate objects. Sometimes, however, what you want is a clone. Inkscape clones are special copies of an object that can be moved around, scaled or rotated at will but remain linked to it. By this we mean that any change to the original is applied to all its clones automatically. If you press Shift-Alt-D, a clone is detached from its ancestor and becomes a fully independent object. Clones can be tiled (Edit→Tile) to create patterns with many kinds of symmetrical or pseudo-random layouts. Reflection, rotation, radial placement and row and column shifting are only a few of the available choices, as shown in Figure 5.
One great thing in Inkscape is its Undo History. Not only can you undo all the changes you have made to a file, but they also are displayed in a nested mode, as shown in Figure 6, which makes it much quicker to go back right to the point you wanted.
Inkscape can convert drawings or parts of drawings to PNG bitmaps. Select File→Export as Bitmap, and remember to choose the right resolution; the default is 90dpi. Besides its native SVG file format, Inkscape also can save your masterpieces in several special formats, including PovRay, LaTeX, encapsulated PostScript, Adobe Illustrator 8, AutoCAD Dxf and OpenDocument drawings.
On the opposite side—importing already-existing graphics—a really neat feature of Inkscape is the capability to generate drawings from LaTeX formulas. Most people, however, will find it much more useful to “trace” JPEG, PNG or GIF images—that is, to convert them to vectorial format. Some advanced Inkscape users even trace the bitmaps that they generated from original vector drawings. The reason for doing this is that the unavoidable degradation may be exactly what is missing to make your work look more realistic.
Normally, if the starting bitmap is simple, the traced version is pretty good. Tracing something as complex as a photograph is theoretically possible, but in practice, the process is often so complex that it greatly slows down Inkscape or simply halts it, depending on the computer. This said, there are many different ways to trace bitmaps with Inkscape. To try them, import a bitmap, select it and then click on Path→Trace Bitmap. In the tracing pane, you'll then be able to generate one or more vectorial paths, starting, for example, from the colors or the levels of brightness of the original image.
Articles about Digital Rights and more at http://stop.zona-m.net CV, talks and bio at http://mfioretti.com
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
Free to Linux Journal readers.Register Now!
- Paranoid Penguin - Building a Secure Squid Web Proxy, Part IV
- SUSE LLC's SUSE Manager
- Google's SwiftShader Released
- Managing Linux Using Puppet
- My +1 Sword of Productivity
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Non-Linux FOSS: Caffeine!
- SourceClear Open
- SuperTuxKart 0.9.2 Released
- Parsing an RSS News Feed with a Bash Script
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide