Safe Haskell	None
Language	Haskell2010

Codec.Picture.Jpg

Description

Module used for JPEG file loading and writing.

Synopsis

Documentation

decodeJpeg :: ByteString -> Either String DynamicImage Source

Try to decompress a jpeg file and decompress. The colorspace is still YCbCr if you want to perform computation on the luma part. You can convert it to RGB using convertImage from the ColorSpaceConvertible typeclass.

This function can output the following pixel types :

PixelY8
- PixelYA8
- PixelRGB8
- PixelYCbCr8

decodeJpegWithMetadata :: ByteString -> Either String (DynamicImage, Metadatas) Source

Equivalent to decodeJpeg but also extracts metadatas.

Extract the following metadatas from the JFIF bloc:

DpiX
DpiY

Exif metadata are also extracted if present.

encodeJpegAtQuality Source

Arguments

:: Word8	Quality factor
-> Image PixelYCbCr8	Image to encode
-> ByteString	Encoded JPEG

Function to call to encode an image to jpeg. The quality factor should be between 0 and 100 (100 being the best quality).

encodeJpegAtQualityWithMetadata Source

Arguments

:: Word8	Quality factor
-> Metadatas
-> Image PixelYCbCr8	Image to encode
-> ByteString	Encoded JPEG

Equivalent to encodeJpegAtQuality, but will store the following metadatas in the file using a JFIF block:

DpiX
DpiY

encodeJpeg :: Image PixelYCbCr8 -> ByteString Source

Encode an image in jpeg at a reasonnable quality level. If you want better quality or reduced file size, you should use encodeJpegAtQuality