JuicyPixels- Picture loading/serialization (in png, jpeg, bitmap, gif, tga, tiff and radiance)

Safe HaskellNone



Module used for JPEG file loading and writing.



decodeJpeg :: ByteString -> Either String DynamicImage #

Try to decompress and decode a jpeg file. 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 images:

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

Equivalent to decodeJpeg but also extracts metadatas.

Extract the following metadatas from the JFIF block:

Exif metadata are also extracted if present.

encodeJpegAtQuality #


:: 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 #


:: 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:

encodeDirectJpegAtQualityWithMetadata #


:: JpgEncodable px 
=> Word8

Quality factor

-> Metadatas 
-> Image px

Image to encode

-> ByteString

Encoded JPEG

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

This function also allow to create JPEG files with the following color space:

  • Y (Pixel8) for greyscale.
  • RGB (PixelRGB8) with no color downsampling on any plane
  • CMYK (PixelCMYK8) with no color downsampling on any plane

encodeJpeg :: Image PixelYCbCr8 -> ByteString #

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

class (Pixel px, PixelBaseComponent px ~ Word8) => JpgEncodable px #

Helper type class describing all JPG-encodable pixel types

Minimal complete definition

componentsOfColorSpace, encodingState, scanSpecificationOfColorSpace


JpgEncodable PixelCMYK8 # 


additionalBlocks :: Image PixelCMYK8 -> [JpgFrame]

componentsOfColorSpace :: Image PixelCMYK8 -> [JpgComponent]

encodingState :: Int -> Image PixelCMYK8 -> Vector EncoderState

imageHuffmanTables :: Image PixelCMYK8 -> [(JpgHuffmanTableSpec, HuffmanPackedTree)]

scanSpecificationOfColorSpace :: Image PixelCMYK8 -> [JpgScanSpecification]

quantTableSpec :: Image PixelCMYK8 -> Int -> [JpgQuantTableSpec]

maximumSubSamplingOf :: Image PixelCMYK8 -> Int

JpgEncodable PixelYCbCr8 # 


additionalBlocks :: Image PixelYCbCr8 -> [JpgFrame]

componentsOfColorSpace :: Image PixelYCbCr8 -> [JpgComponent]

encodingState :: Int -> Image PixelYCbCr8 -> Vector EncoderState

imageHuffmanTables :: Image PixelYCbCr8 -> [(JpgHuffmanTableSpec, HuffmanPackedTree)]

scanSpecificationOfColorSpace :: Image PixelYCbCr8 -> [JpgScanSpecification]

quantTableSpec :: Image PixelYCbCr8 -> Int -> [JpgQuantTableSpec]

maximumSubSamplingOf :: Image PixelYCbCr8 -> Int

JpgEncodable PixelRGB8 # 


additionalBlocks :: Image PixelRGB8 -> [JpgFrame]

componentsOfColorSpace :: Image PixelRGB8 -> [JpgComponent]

encodingState :: Int -> Image PixelRGB8 -> Vector EncoderState

imageHuffmanTables :: Image PixelRGB8 -> [(JpgHuffmanTableSpec, HuffmanPackedTree)]

scanSpecificationOfColorSpace :: Image PixelRGB8 -> [JpgScanSpecification]

quantTableSpec :: Image PixelRGB8 -> Int -> [JpgQuantTableSpec]

maximumSubSamplingOf :: Image PixelRGB8 -> Int

JpgEncodable Pixel8 # 


additionalBlocks :: Image Pixel8 -> [JpgFrame]

componentsOfColorSpace :: Image Pixel8 -> [JpgComponent]

encodingState :: Int -> Image Pixel8 -> Vector EncoderState

imageHuffmanTables :: Image Pixel8 -> [(JpgHuffmanTableSpec, HuffmanPackedTree)]

scanSpecificationOfColorSpace :: Image Pixel8 -> [JpgScanSpecification]

quantTableSpec :: Image Pixel8 -> Int -> [JpgQuantTableSpec]

maximumSubSamplingOf :: Image Pixel8 -> Int