JPEG-PIL JPEG (ISO 10918)

Extensions: .jfif, .jpe, .jpg, .jpeg

A JPEG format based on Pillow.

This format supports grayscale, RGB and RGBA images.

Parameters for reading

exifrotatebool

Automatically rotate the image according to exif flag. Default True.

pilmodestr

From the Pillow documentation:

  • ‘L’ (8-bit pixels, grayscale)

  • ‘P’ (8-bit pixels, mapped to any other mode using a color palette)

  • ‘RGB’ (3x8-bit pixels, true color)

  • ‘RGBA’ (4x8-bit pixels, true color with transparency mask)

  • ‘CMYK’ (4x8-bit pixels, color separation)

  • ‘YCbCr’ (3x8-bit pixels, color video format)

  • ‘I’ (32-bit signed integer pixels)

  • ‘F’ (32-bit floating point pixels)

PIL also provides limited support for a few special modes, including ‘LA’ (‘L’ with alpha), ‘RGBX’ (true color with padding) and ‘RGBa’ (true color with premultiplied alpha).

When translating a color image to grayscale (mode ‘L’, ‘I’ or ‘F’), the library uses the ITU-R 601-2 luma transform:

L = R * 299/1000 + G * 587/1000 + B * 114/1000
as_graybool

If True, the image is converted using mode ‘F’. When mode is not None and as_gray is True, the image is first converted according to mode, and the result is then “flattened” using mode ‘F’.

Parameters for saving

qualityscalar

The compression factor of the saved image (1..100), higher numbers result in higher quality but larger file size. Default 75.

progressivebool

Save as a progressive JPEG file (e.g. for images on the web). Default False.

optimizebool

On saving, compute optimal Huffman coding tables (can reduce a few percent of file size). Default False.

dpituple of int

The pixel density, (x,y).

icc_profileobject

If present and true, the image is stored with the provided ICC profile. If this parameter is not provided, the image will be saved with no profile attached.

exifdict

If present, the image will be stored with the provided raw EXIF data.

subsamplingstr

Sets the subsampling for the encoder. See Pillow docs for details.

qtablesobject

Set the qtables for the encoder. See Pillow docs for details.