render
render(filename [, {format, quality}]) {void}
Renders the web page to an image buffer and saves it as the specified filename.
Currently, the output format is automatically set based on the file extension.
Supported formats
- PNG
- JPEG
- BMP
- PPM
- GIF support depends on the build of Qt used
Quality
An integer between 0 and 100.
The quality setting only has an effect on jpeg and png formats. With jpeg, it sets the quality level as a percentage, in the same way as most image editors. (The output file always has 2x2 subsampling.) A level of 0 produces a very small, very low quality file, and 100 produces a much larger, high-quality file. The default level is 75. With png, it sets the lossless (Deflate) compression level, with 0 producing the smallest files, and 100 producing the largest. However, the files look identical, and are always true-colour.
Examples
var webPage = require('webpage');
var page = webPage.create();
page.viewportSize = { width: 1920, height: 1080 };
page.open("http://www.google.com", function start(status) {
page.render('google_home.jpeg', {format: 'jpeg', quality: '100'});
phantom.exit();
});
More information
The image generation code (except for PDF output) uses QImage from the Qt framework, documented at http://doc.qt.io/qt-5/qimage.html#save.