JPEGJUDGE(1) General Commands Manual JPEGJUDGE(1)NAME
jpegjudge - guess jpeg picture quality
SYNOPSIS
jpegjudge [ -V ]
jpegjudge [ -b ] file ...
DESCRIPTION
Jpegjudge reads each argument and attempts to guess the quality with which it was saved. Currently, only a rough indicator is calculcated,
ranging from 0 (lowest quality) to 1000 (highest quality), an extension to other formats would be straightforward, but isn't planned.
It can read all pictures the IJG jpeg library can read, i.e. normal and progressive jpeg's.
OPTIONS
-b Display only quality indicator, suppress other information (filenames).
-h, --help
Display short summary of options.
-V, --version
Display version number and exit.
BUGS
It should be possible to judge pictures stored in non-lossy formats, too, since conversion to jpeg may influence the measurement.
The quality indicator is non-linear, and could be much better.
The algorithm to calculate the quality was made up in 10 minutes, after staring at various histograms.
ACKNOWLEDGEMENTS
This program contains code from the IJG jpeg software.
Jpegjudge - guess jpeg picture quality JPEGJUDGE(1)
Check Out this Related Man Page
img-jpeg(n) img-jpeg(n)
__________________________________________________________________________________________________________________________________________________NAME
img-jpeg - Img, Joint Picture Expert Group format (jpeg)
SYNOPSIS
package require Tk
package require img::jpeg ?1.4?
image create photo ?name? ?options?
_________________________________________________________________DESCRIPTION
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.
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. 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.
JPEG OPTIONS
The handler provides six options, two effective when reading from a JPEG image, and five influencing the writing of such. One option is
usable for both reading an writing.
-fast This option is for reading from JPEG data. It usage 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. It usage causes the writer to optimize the huffman table used to encode the jpeg coefficients.
-progressive
This option is for writing JPEG data. It usage causes the creation of a progressive JPEG file.
SEE ALSO
img-bmp, img-dted, 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
KEYWORDS
image handling, jpeg, tk
COPYRIGHT
Copyright (c) 1995-2009 Jan Nijtmans <nijtmans@users.sourceforge.net>
Img 1.4 img-jpeg(n)