Google WebP Reader/Writer

The WebP format was developed by Google. WebP is a method of lossy and lossless compression that can be used on a large variety of photographic, translucent, and graphical images found on the web.

The information below originated from the Google Developers website. Please refer to the website for detailed information.

From: A new image format for the Web

WebP lossless images are 26% smaller in size compared to PNGs. WebP lossy images are 25-34% smaller than comparable JPEG images at equivalent SSIM quality index.

Lossless WebP supports transparency (also known as alpha channel) at a cost of just 22% additional bytes. For cases when lossy RGB compression is acceptable, lossy WebP also supports transparency, typically providing 3× smaller file sizes compared to PNG.

How WebP Works

Lossy WebP compression uses predictive coding to encode an image, the same method used by the VP8 video codec to compress keyframes in videos. Predictive coding uses the values in neighboring blocks of pixels to predict the values in a block, and then encodes only the difference.

Lossless WebP compression uses already seen image fragments in order to exactly reconstruct new pixels. It can also use a local palette if no interesting match is found.

WebP Compression Techniques

Google WebP Product and System Requirements

Format

FME Platform

Operating System

Reader/Writer

FME Form

FME Flow

FME Flow Hosted

Windows 64-bit

Linux

Mac

Reader

Yes

Yes

Yes

Yes

Yes

Yes

Writer

Yes

Yes

Yes

Yes

Yes

Yes

Reader Overview

FME considers a single WebP file to be a dataset.

Writer Overview

FME considers a dataset to be a folder name. The feature type of each dataset is the filename.

FME Raster Features

FME raster features represent raster data and use several concepts that are unlike those used in the handling of vector data.

For comprehensive information about how FME processes raster data, see Rasters.

WebP files can only be written with square pixel dimensions.

WebP only supports rasters with a Red8, a Green8, a Blue8 band, and optionally an Alpha8 band.