Readonlyhastrue when the source WebP carried an alpha channel.
ReadonlyheightImage height in pixels.
ReadonlyrgbaDecoded pixels as 8-bit RGBA, one byte per channel (R,G,B,A), row-major
from the top-left. Length is exactly width * height * 4 bytes. Ready to
wrap in an ImageData or upload as a WebGL/WebGPU texture. Alpha is always
present in this buffer; when WebpImageData.hasAlpha is false every
alpha byte is 255.
ReadonlywidthImage width in pixels.
A decoded WebP image: RGBA8 pixels plus dimensions, as returned by WebpDecoder.decode.