img-jpeg - Img, Joint Picture Expert Group format (jpeg)
package require Tk
package require img::jpeg ?1.4?
image create photo ?name?
?options?
package require img::jpeg.
Like all packages of Img it does not provide new
commands, but extends the existing Tk command image so that it
supports files containing raster images in the Joint Picture Expert Group
format (jpeg). More specifically img::jpeg extends Tk's
photo image type.
The name of the new format handler is jpeg.
The package img::jpeg is a sub-package of Img. It
can be loaded as a part of the complete Img support, via package require
Img, or on its own, via package require img::jpeg.
This handler provides new additional configuration options. See
section JPEG OPTIONS for more detailed explanations.
All of the above means that in a call like
- image create
photo ?name? ?options?
- [1]
- Image data in jpeg format (options -data and -file) is
detected automatically.
- [2]
- The format name jpeg is recognized by the option -format. In
addition the value for the option is treated as list and may contain any
of the special options listed in section JPEG OPTIONS.
The handler provides the following options:
- -fast
- This option is for reading from JPEG data. If specified, it activates a
processing mode which is fast, but also provides only low-quality
information.
- -grayscale
- This option can be used for both reading and writing of JPEG data. Usage
of this option forces incoming images to grayscale, and written images
will be monochrome.
- -quality
n
- This option is for writing JPEG data. It specifies the compression level
as a quality percentage. The higher the quality, the less the compression.
The nominal range for n is 0...100. Useful values are
in the range 5...95. The default value is 75.
- -smooth
n
- This option is for writing JPEG data. When used the writer will smooth the
image before performing the compression. Values in the
10...30 are usually enough. The default is 0, i.e no
smoothing.
- -optimize
- This option is for writing JPEG data. If specified, it causes the writer
to optimize the Huffman table used to encode the JPEG coefficients.
- -progressive
- This option is for writing JPEG data. If specified, it causes the creation
of a progressive JPEG file.
img-bmp, img-dted, img-flir, img-gif, img-ico, img-intro,
img-jpeg, img-pcx, img-pixmap, img-png, img-ppm, img-ps, img-raw, img-sgi,
img-sun, img-tga, img-tiff, img-window, img-xbm, img-xpm
Copyright (c) 1995-2023 Jan Nijtmans <nijtmans@users.sourceforge.net>