README
¶
Native WebP for Go
This is a native WebP encoder written entirely in Go, with no dependencies on libwebp or other external libraries. Designed for performance and efficiency, this encoder generates smaller files than the standard Go PNG encoder and is approximately 50% faster in execution.
Currently, the encoder supports only WebP lossless images (VP8L).
Decoding Support
We provide WebP decoding through a wrapper around golang.org/x/image/webp, enhancing it with basic VP8X support to enable applications to process a broader range of WebP images.
Benchmark
We conducted a quick benchmark to showcase file size reduction and encoding performance. Using an image from Google’s WebP Lossless and Alpha Gallery, we compared the results of our nativewebp encoder with the standard PNG encoder.
For the PNG encoder, we applied the png.BestCompression setting to achieve the most competitive compression outcomes.
| PNG encoder | nativeWebP encoder | reduction | ||
|---|---|---|---|---|
|
file size | 120 kb | 96 kb | 20% smaller |
| encoding time | 42945049 ns/op | 27716447 ns/op | 35% faster | |
|
file size | 46 kb | 36 kb | 22% smaller |
| encoding time | 98509399 ns/op | 31461759 ns/op | 68% faster | |
|
file size | 236 kb | 194 kb | 18% smaller |
| encoding time | 178205535 ns/op | 102454192 ns/op | 43% faster | |
|
file size | 53 kb | 41 kb | 23% smaller |
| encoding time | 29088555 ns/op | 14959849 ns/op | 49% faster | |
|
file size | 139 kb | 123 kb | 12% smaller |
| encoding time | 63423995 ns/op | 21717392 ns/op | 66% faster |
image source: https://developers.google.com/speed/webp/gallery2
Installation
To install the nativewebp package, use the following command:
go get github.com/HugoSmits86/nativewebp
Usage
Here’s a simple example of how to encode an image:
file, err := os.Create(name)
if err != nil {
log.Fatalf("Error creating file %s: %v", name, err)
}
defer file.Close()
err = nativewebp.Encode(file, img, nil)
if err != nil {
log.Fatalf("Error encoding image to WebP: %v", err)
}
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Decode ¶ added in v1.0.0
Decode reads a WebP image from the provided io.Reader and returns it as an image.Image.
This function is a wrapper around the underlying WebP decode package (golang.org/x/image/webp). It supports both lossy and lossless WebP formats, decoding the image accordingly.
Parameters:
r - The source io.Reader containing the WebP encoded image.
Returns:
The decoded image as image.Image or an error if the decoding fails.
func DecodeConfig ¶ added in v1.0.0
DecodeConfig reads the image configuration from the provided io.Reader without fully decoding the image.
This function is a wrapper around the underlying WebP decode package (golang.org/x/image/webp) and provides access to the image's metadata, such as its dimensions and color model. It is useful for obtaining image information before performing a full decode.
Parameters:
r - The source io.Reader containing the WebP encoded image.
Returns:
An image.Config containing the image's dimensions and color model, or an error if the configuration cannot be retrieved
func Encode ¶
Encode writes the provided image.Image to the specified io.Writer in WebP format.
This function always encodes the image using VP8L (lossless WebP). If `UseExtendedFormat` is enabled, it wraps the VP8L frame inside a VP8X container, allowing the use of metadata such as EXIF, ICC color profiles, or XMP metadata.
Note: VP8L already supports transparency, so VP8X is **not required** for alpha support.
Parameters:
w - The destination writer where the encoded WebP image will be written.
img - The input image to be encoded.
o - Pointer to Options containing encoding settings:
- UseExtendedFormat: If true, wraps the image in a VP8X container to enable
extended WebP features like metadata.
Returns:
An error if encoding fails or writing to the io.Writer encounters an issue.
Types ¶
type Options ¶ added in v0.9.3
type Options struct {
UseExtendedFormat bool
}
Options holds configuration settings for WebP encoding.
Currently, it provides a flag to enable the extended WebP format (VP8X), which allows for metadata support such as EXIF, ICC color profiles, and XMP.
Fields:
- UseExtendedFormat: If true, wraps the VP8L frame inside a VP8X container to enable metadata support. This does not affect image compression or encoding itself, as VP8L remains the encoding format.
Source Files