Graphics.ThumbnailPlus.ImageSize

Detect the image size without opening the image itself.

Amazingly, reimplementing this wheel is the recommended way of not processing huge images according to gd's FAQ. We hope to be at least as restrictive as gd itself is, otherwise some malicious image could get past this code and blow on gd's hand.

This code has been ressurected by the now-deprecated imagesize-conduit library by Michael Snoyman.

Documentation

data Size

Constructors

Size

Fields

width :: Int

height :: Int

Instances

Eq Size

Ord Size

Read Size

Show Size

Typeable Size

data FileFormat

Constructors

GIF

PNG

JPG

Instances

Enum FileFormat

Eq FileFormat

Ord FileFormat

Read FileFormat

Show FileFormat

Typeable FileFormat

sinkImageInfo :: Monad m => Consumer ByteString m (Maybe (Size, FileFormat))

Find out the size of an image. Also returns the file format that parsed correctly. Note that this function does not verify that the file is indeed in the format that it returns, since it looks only at a small part of the header.