[reportlab-users] How can I insert CMYK JPG in CMYK pdf document ?

[KLEIN Stéphane]

Le Mon, 27 Jul 2009 06:35:32 -0700, Chuck Martin a écrit :


> I believe that jpg does not support cmyk. When I want CMYK I use tif.

> 

> Since there is no perfect mapping from RGB to CMYK, my images start out

> as eps with CMYK colors. Then I use ghostscript to convert them to tif.

> If your images start out as RGB bitmaps, then there is less benefit in

> converting them to tif.


Exemple :

stephane at stephane-desktop:$ identify -verbose 001.jpg 
Image: 001.jpg
  Format: JPEG (Joint Photographic Experts Group JFIF format)
  Class: DirectClass
  Geometry: 768x591+0+0
  Resolution: 300x300
  Print size: 2.56x1.97
  Units: PixelsPerInch
  Type: ColorSeparation
  Endianess: Undefined
  Colorspace: CMYK
  Depth: 8-bit
  Channel depth:
    cyan: 8-bit
    magenta: 8-bit
    yellow: 8-bit
    black: 8-bit
  Channel statistics:
    cyan:
      min: 0 (0)
      max: 252 (0.988235)
      mean: 152.341 (0.597416)
      standard deviation: 60.3994 (0.236861)
    magenta:
      min: 0 (0)
      max: 255 (1)
      mean: 140.976 (0.552848)
      standard deviation: 57.7572 (0.226499)
    yellow:
      min: 0 (0)
      max: 255 (1)
      mean: 149.838 (0.5876)
      standard deviation: 60.2478 (0.236266)
    black:
      min: 0 (0)
      max: 252 (0.988235)
      mean: 159.42 (0.625175)
      standard deviation: 82.0791 (0.321879)
  Total ink density: 324%
  Rendering intent: Undefined
  Interlace: None
  Background color: white
  Border color: cmyk(223,223,223,0)
  Matte color: grey74
  Transparent color: black
  Page geometry: 768x591+0+0
  Dispose: Undefined
  Iterations: 0
  Compression: JPEG
  Quality: 85
  ...