Computer Science – 1.3 Compression | e-Consult
1.3 Compression (1 questions)
Vector graphics are typically compressed using techniques that reduce redundancy in the description of the shapes and paths that make up the graphic. This can involve several methods:
- Path Simplification: Reducing the number of points and curves required to represent a shape, thereby reducing the amount of data.
- Dictionary Encoding: Storing frequently used path segments (e.g., lines, curves) in a dictionary and referencing them in the graphic description.
- Run-Length Encoding (for specific formats): Some vector formats might use RLE to compress sequences of identical commands.
SVG (Scalable Vector Graphics): SVG is an XML-based vector graphics format. It typically uses a combination of text-based descriptions and compact encoding of path commands. SVG can be compressed using GZIP, which is effective for text-based data. Advantages: It's a widely supported open standard, easily editable with text editors, and supports animation and interactivity. Disadvantages: Can result in larger file sizes compared to some other vector formats, especially for complex graphics.
EPS (Encapsulated PostScript): EPS is a binary vector graphics format that uses PostScript, a page description language. It often employs compression techniques specific to PostScript, such as run-length encoding and dictionary encoding. Advantages: Generally produces smaller file sizes than SVG for complex graphics, and is well-suited for professional printing. Disadvantages: Less easily editable than SVG (requires PostScript knowledge), and is less widely supported in web browsers. It's also considered less secure than SVG due to the potential for malicious PostScript code.
Impact on Scalability and Editability: Both formats are inherently scalable because they are based on mathematical descriptions of shapes. Compression should not significantly affect scalability. Editability is generally better in SVG due to its text-based nature. EPS is more difficult to edit directly, requiring specialized software.