phash

func Compute ¶

func Compute(r io.ReadSeeker) (string, error)

Compute reads an image from r, decodes it, and returns a 16-char hex pHash string. Returns empty string and nil error for unsupported/undecodable/oversized image formats. Returns empty string and error only for hashing failures on successfully decoded images.

r must be seekable: the image header is inspected first (via DecodeConfig) to reject oversized images before the full decode allocates pixel memory, then r is rewound for the full decode.