Sterling is a

fractal In mathematics, a fractal is a Shape, geometric shape containing detailed structure at arbitrarily small scales, usually having a fractal dimension strictly exceeding the topological dimension. Many fractals appear similar at various scale ...

-generating

computer program A computer program is a sequence or set of instructions in a programming language for a computer to Execution (computing), execute. It is one component of software, which also includes software documentation, documentation and other intangibl ...

written in the C programming language in 1999 for

Microsoft Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

by Stephen C. Ferguson. Sterling is now

freeware Freeware is software, often proprietary, that is distributed at no monetary cost to the end user. There is no agreed-upon set of rights, license, or EULA that defines ''freeware'' unambiguously; every publisher defines its own rules for the free ...

while Sterling2 is a freeware version of Sterling with different

algorithm In mathematics and computer science, an algorithm () is a finite sequence of Rigour#Mathematics, mathematically rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algo ...

s. It was released in September 2008 by Tad Boniecki. Apart from the name (which shows as sterlingwar2 in the title bar and on the About screen), the program looks just like the original Sterling. The only internals that are different are the 50 formulae for fractal generation. Parameter files made by Sterling can be used in Sterling2 and vice versa, though they will draw different images. Sterling is based on the notion that one way to generate interesting fractal images is by using elaborate color filters and shading. In many images, the main interest lies in the filters rather than the actual fractal boundaries themselves, as in traditional fractal-generating programs. The fractal merely serves as a seeding function to the coloring

s and filters. A feature of Sterling is the richness of the renders. Sterling has a simple GUI interface with a limited number of functions. The program saves files as

JPEG JPEG ( , short for Joint Photographic Experts Group and sometimes retroactively referred to as JPEG 1) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degr ...

, BMP or one of six other formats. It draws in

Julia Julia may refer to: People *Julia (given name), including a list of people with the name *Julia (surname), including a list of people with the name *Julia gens, a patrician family of Ancient Rome *Julia (clairvoyant) (fl. 1689), lady's maid of Qu ...

mode, allows inside-out rendering and does

anti-aliasing Anti-aliasing may refer to any of a number of techniques to combat the problems of aliasing in a sampled signal such as a digital image or digital audio recording. Specific topics in anti-aliasing include: * Anti-aliasing filter, a filter used b ...

. It offers 32 different renders and four transform effects. There are three independent color controls and two ways to zoom into an image. The Sterling2 ZIP file (436 KB) contains brief instructions. There is no installation — it is enough to put the executable and

dynamic-link library A dynamic-link library (DLL) is a shared library in the Microsoft Windows or OS/2 operating system. A DLL can contain executable code (functions), data, and resources. A DLL file often has file extension .dll even though this is not required ...

files in the same directory and start the exe file. In 2018, the original code for sterling was released under the

GPLv3 The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first ...

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Sample images

Image:Fractal Sentinel SterlingW3165.jpg Image:Fractal tower Sterling2 1837.jpg Image:Fractal red flare Sterling2 2831.jpg Image:Sterling2 4728aa.jpg Image:Baroque bug fractal SterlingW2589.jpg Image:Sterling2 4906aa4.jpg

References

External links

* Sterling2 (freeware) home pag

including download, instructions and sample images. {{Computer science Free software programmed in C Fractal software 1999 software Formerly proprietary software Windows-only free software