GIS Question of the Day # 6 - Symbol Format

Question:

In ArcGIS, what type of format is used for symbology i.e. png or svg?

Answer:

In ArcGIS, symbology can utilize various formats for icons and symbols, with the most common being PNG and SVG formats. Here’s a brief overview of these formats and their use in ArcGIS:

PNG (Portable Network Graphics)

• Description: A raster graphics file format that supports lossless data compression.

• Usage:

  • Commonly used for icons and symbols in ArcGIS due to its support for transparency and high-quality images.

  • Ideal for complex images with gradients, shadows, and other detailed graphics.

• Pros:

  • High-quality images with support for transparency.

  • Widely supported across different platforms and applications.

• Cons:

  • Larger file sizes compared to vector formats like SVG.

  • Not scalable without losing quality.

SVG (Scalable Vector Graphics)

• Description: A vector graphics format that uses XML to describe two-dimensional graphics.

• Usage:

  • Often used for symbols in ArcGIS due to its scalability and ability to retain quality at any size.

  • Ideal for simple, geometric shapes and icons that need to be resized frequently.

• Pros:

  • Scalable without loss of quality.

  • Typically smaller file sizes compared to raster images.

  • Easily editable and customizable.

• Cons:

  • Can be more complex to create and edit compared to raster images.

  • Not suitable for complex images with detailed textures or gradients.

Choosing Between PNG and SVG

• Use PNG:

  • When you need high-quality, detailed images with transparency.

  • For raster-based symbology where the image complexity is high and does not require frequent resizing.

• Use SVG:

  • When you need scalable icons and symbols that maintain quality at any size.

  • For vector-based symbology where geometric shapes and simple designs are predominant.

Implementation in ArcGIS

• ArcGIS Pro: Supports both PNG and SVG formats for symbols. You can import custom symbols in these formats through the symbology pane.

• ArcGIS Online: Also supports both PNG and SVG for web maps and applications. Custom symbols can be uploaded and used in web maps, dashboards, and other applications.

• Symbology Libraries: ArcGIS provides a range of built-in symbols and icons in both PNG and SVG formats, which can be customized and used directly in your maps and applications.

By selecting the appropriate format based on your needs, you can ensure that your symbology is both high-quality and functional within your ArcGIS projects.