VMOD image provides a tool for image modification and optimization.
VMOD image is available through the package varnish-plus-vmods-extras.
import image;
import headerplus;
sub vcl_backend_response {
headerplus.init(beresp);
if (beresp.http.content-type == "image/jpeg" ||
beresp.http.content-type == "image/png") {
if (bereq.http.Accept ~ "image/webp") {
image.webp();
}
headerplus.attr_set("Vary", "Accept");
}
headerplus.write();
}
VOID webp([INT quality = 75], [INT resize_width], [INT resize_height], [BOOL lossless = false], [INT lossless_level = 6])
Convert an image to the WebP format and store it in cache. Optionally scale, resize or change the quality of conversion. Scaling is done by using only one of resize_width or resize_height. quality and lossless are mutually exclusive options. The supported content types to convert are image/png and image/jpeg. When called this function disables streaming. It should not be re-enabled for proper functionality.
Arguments
INT quality - The compression quality, between 0 and 100. A lower number will result in a smaller size but lower quality.INT resize_width - Change the width of the converted image. Can scale the image to the width when only setting this parameter.INT resize_height - Change the height of the converted image. Can scale the image to the height when only setting this parameter.BOOL lossless - Enable lossless compression. When enabled quality is ignored and lossless_level is used instead.INT lossless_level - Set the compression mode, between 0 and 9. A lower number is faster but produces a larger file size.Returns
Nothing.