PNG (Portable Network Graphics) Reader/Writer

FME Format Type Identifier

PNGRASTER

Reader/Writer

Both

Raster/Vector

Raster

Typical File Extensions

.png

PNG is an image format that supports a wide range of classified and continuous color models.

The PNG format can only support up to 256 palette colors as a classified image, but can support both 1- and 2-byte RGB, RGBA, and grayscale continuous images.

The format was introduced in 1995 as a replacement format for GIF, specifically implemented so that it does not require a patent to use compression.

Note: The PNG writer writes rasters, not vector features that become rasters.

PNG Product and System Requirements

Format

Product

Operating System

Reader/Writer

FME Desktop License

FME Server

FME Cloud

Windows

Linux

Mac

Reader

Available in FME Professional Edition and higher

Yes

Yes

64-bit: Yes

Yes

Yes

Writer

Available in FME Professional Edition and higher

Yes

Yes

64-bit: Yes

Yes

Yes

Reader Overview

FME considers a single PNG file to be a dataset. The PNG file contains pixel data, and each pixel in the file is a point in a single FME raster feature.

Writer Overview

FME considers a dataset to be a folder name.

FME Raster Features

FME raster features represent raster data and use several concepts that are unlike those used in the handling of vector data. The topics below describe how FME processes raster data.

About FME Rasters Tiling and Mosaicking
Raster Properties Band Combining and Separating
Band Properties Band and Palette Selection
Palette Properties Raster Processing
Compression Raster versus Vector Features
Pyramiding Raster File Naming
Interleaving World Files
Interpretation and Data Type TAB Files
Palette Resolution  

PNG files can only be written with square pixel dimensions.

PNG supports rasters with the following band structures:

  • Red, Green, Blue
  • Red, Green, Blue, Alpha
  • Gray
  • Gray, Alpha
  • UInt8 with an RGBA32 palette