资源下载

• webp-imageio
• libwebp-1.0.1 for linux/maxc
• libwebp-1.0.1 for windows
• CMake-3.12.4 for linux
• CMake-3.12.4 for mac
• CMake-3.12.4 for win64-x64
• CMake-3.12.4 for win32-x86

Description

Java Image I/O reader and writer for the Google WebP image format.

License

webp-imageio is distributed under the Apache Software License version 2.0.

Usage

• Add webp-imageio.jar to the classpath of your application
• Ensure libwebp-imageio.so, libwebp-imageio.dylib or webp-imageio.dll is accessible on the Java native library path (java.library.path system property)
• The WebP reader and writer can be used like any other Image I/O reader and writer.

Decoding

WebP images can be decoded using default settings as follows.

BufferedImage image = ImageIO.read(new File("input.webp"));

To customize the WebP decoder settings you need to create instances of ImageReader and WebPReadParam.

// Obtain a WebP ImageReader instance
ImageReader reader = ImageIO.getImageReadersByMIMEType("image/webp").next();// Configure decoding parameters
WebPReadParam readParam = new WebPReadParam();
readParam.setBypassFiltering(true);// Configure the input on the ImageReader
reader.setInput(new FileImageInputStream(new File("input.webp")));// Decode the image
BufferedImage image = reader.read(0, readParam);

Encoding

Encoding is done in a similar way to decoding.

You can either use the Image I/O convenience methods to encode using default settings.

// Obtain an image to encode from somewhere
BufferedImage image = ImageIO.read(new File("input.png"));// Encode it as webp using default settings
ImageIO.write(image, "webp", new File("output.webp"));

Or you can create an instance of ImageWriter and WebPWriteParam to use custom settings.

// Obtain an image to encode from somewhere
BufferedImage image = ImageIO.read(new File("input.png"));// Obtain a WebP ImageWriter instance
ImageWriter writer = ImageIO.getImageWritersByMIMEType("image/webp").next();// Configure encoding parameters
WebPWriteParam writeParam = new WebPWriteParam(writer.getLocale());
writeParam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
writeParam.setCompressionType(p.getCompressionTypes()[WebPWriteParam.LOSSLESS_COMPRESSION]);// Configure the output on the ImageWriter
writer.setOutput(new FileImageOutputStream(new File("output.webp")));// Encode
writer.write(null, new IIOImage(image, null, null), writeParam);

Compiling

Compiling the native library for Java SE

• Install CMake 2.8 or newer. CMake can be downloaded from www.cmake.org or installed using your systems package manager.
• Create a directory called build in the root of the project
• Open a terminal and navigate to the newly created 'build' directory
• Run cmake .. in the 'build' directory to generate the build scripts for your system.
• cmake --build . to compile the library
• The compiled library can be found under the directory build/src/main/c

Compiling the native library for Android

• Install the Android NDK.
• Run ndk-build in the src/android directory
• After completion libwebp-imageio.so can be found under src/android/libs/<abi>

Compiling the Java library

Using Gradle

• Run ./gradlew build -x test in the root of the project
• The compiled Java library can be found under the build directory