Semantic Model Mail Archive: SM> FW: Re: PWG Review of the I

Semantic Model Mail Archive: SM> FW: Re: PWG Review of the I

SM> FW: Re: PWG Review of the IPP Color and Imaging Attributes versio n 0.1, Thur, 12/5/02, 1-2 PM EST

From: Hastings, Tom N (hastings@cp10.es.xerox.com)
Date: Wed Dec 04 2002 - 17:07:34 EST

  • Next message: Zehler, Peter: "SM> PWG Semantic Model Schema v0.90 available"

    Here is a suggestion from Michael Sweet to add a 'bi-cubic' value to the
    "resample-method" Job Template attribute proposal. The "resample-method"
    Job Template attribute is itself proposed to be added to the IPP Color and
    Imaging Spec.

    Comments?

    Tom

    -----Original Message-----
    From: Hastings, Tom N
    Sent: Wednesday, December 04, 2002 13:56
    To: 'digital_printing@cip4.org'
    Subject: RE: CIP4 Forum Digital Printing: Re: PWG Review of the IPP
    Color and Imaging Attributes version 0.1, Thur, 12/5/02, 1-2 PM EST

    How about this definition for "bicubic" (no hyphen) from Delmar's Dictionary
    of Digital Printing & Publishing:

    Bicubic Interpolation - The use of two cubic functions to generate
    interpolated values along a geometric surface. Cubic functions are more
    accurate than linear functions, and more difficult to compute, but yield
    superior results.

    So making it parallel to the bi-linear definition of:

    'bi-linear' A method used to resample image data (pixels) from one
    resolution to another that is accomplished by using the weighted sum of the
    four nearest pixel values in the source image to compute the replacement
    pixel in the output (resampled) image. This method would give higher image
    quality than nearest-neighbor but would take more time to compute.
    The algorithm to determine the "weighted sum" is implementation dependent.

    we'd have:

    'bi-cubic' A method used to resample image data (pixels) from one
    resolution to another that is accomplished by using the weighted sum of two
    cubic functions of pixel values in the source image to compute the
    replacement pixel in the output (resampled) image. This method would give
    higher image quality than 'bi-linear' but would take more time to compute.

    The algorithm to determine the "weighted sum" and the two cubic functions is
    implementation dependent.

    Tom

    -----Original Message-----
    From: mike@easysw.com [mailto:mike@easysw.com]
    Sent: Wednesday, December 04, 2002 13:22
    To: hastings@cp10.es.xerox.com
    Subject: CIP4 Forum Digital Printing: Re: PWG Review of the IPP Color
    and Imaging Attributes version 0.1, T hur, 12/5/02, 1-2 PM EST

    Hastings, Tom N wrote:
    > ...
    > We need to consider adding 'linear' and 'cubic' (or bicubic) with good
    > definitions.

    bi-cubic should definitely be added; linear and cubic are probably
    not appropriate unless you have a 1-pixel wide or height image.

    > ...
    > Also Acrobat can apply resampling independently to color bit map images,
    > gray-scaled bit map images, and monochrome bit map images.

    I think we can leave that to the PDL to define; the resample-method
    attribute can specify the default setting and the PDL data can/may
    override it.

    -- 
    ______________________________________________________________________
    Michael Sweet, Easy Software Products                  mike@easysw.com
    Printing Software for UNIX                       http://www.easysw.com
    

    ----- This message was submitted by Message URL: http://www.cip4.org/intern/groups/email_details.php?eid=4184 Forum URL: http://www.cip4.org/intern/groups/email_forum.php?gid=2



    This archive was generated by hypermail 2b29 : Wed Dec 04 2002 - 17:07:51 EST