ProfitPress Mega CDROM2 …eeware (MSDOS)(1992)(Eng)/ProfitPress-MegaCDROM2.B6I/WINDOWS/MISC/WINJP095.ZIP/WINJPEG.DOC

Text File | 1992-05-23 | 7.9 KB | 192 lines

                            WinJPEG v.0.95
                         by Norman and Ken Yee

Introduction
------------

    WinJPEG v1.00 is an image viewer for Microsoft Windows 3.x with the
following features:

    - display JPEG, *TARGA, or GIF images
    - export an image to JPEG, *TARGA, GIF, Windows BMP, or OS/2 BMP format
    - 1-pass/2-pass quantization, Floyd-Steinberg dithering
    - adjust amount of red, green, and blue in an image
    - adjust hue, saturation, and intensity
    - rotate image, flip the image vertically/horizontally
    - *image magnification/reduction
    - *batch file conversion of GIFs or TARGAs to JPEG
    - *slideshow: display selected files sequentially

* means that feature is not implemented yet.

    There are two versions of WinJPEG.  One is a plain JPEG/GIF viewer
and the second is the full version with the features listed above.  The full
version is about 10% slower than the other one.


Memory Usage
------------

We suggest that you have at least:

  1) 4 Mb of memory according to Windows (under the "Help"/"About
     Program Manager" menu item of Program Manager) or
  2) 2 Mb physical memory (with no Windows swap disk/file) and sufficient
     space for a temporary file.

    WinJPEG can use a temporary file or available memory.  If you choose
the temporary file option, the temporary drive should have free space
that is at least three times the area of a selected image in bytes (e.g., a
1024x1024 image would need 1024x1024x3 bytes or 3 Mb of disk space).  If
you do not have enough space for the temporary file, WinJPEG will warn
you and continue.  However, the image will be garbled: portions of the
image may be repeated.
    When you select "Use available memory" under "Memory options,"
WinJPEG will use the available physical and virtual memory.  If there
isn't enough memory for the decoding routines, a temporary file will
automatically be used.
    You may want to play around with these memory options to determine
what is optimum for your system configuration.  The choice between using
available memory and using a temporary file depends on the size of the
image and how much physical memory you have.  Generally, if you don't
have much physical memory(less than 4 Mb), stick with the temporary file
for optimum speed.  If you have at least 8Meg of physical memory, it may
display faster if you select "Use available memory."  If you have memory
that is between these two thresholds, you should use available memory for
small images and use a temporary file for large(greater than 800x600)
images.
    A large amount of memory is needed for 2-pass quantization; if you do
not have enough free memory, you may still be able to view the image by
selecting the 1-pass quantization display option.


JPEG Display/Save Options
-------------------------

    You can select 1-pass or 2-pass quantization and whether dithering
should be used.  1-pass quantization is faster than the 2-pass option but
the output generally looks more grainy.  Also, 2-pass quantization
requires more memory so it may be even slower because the routines will
swap to hard disk when they run out of physical memory.
    The dithering method is Floyd-Steinberg; dithering is useful when
quantizing to 256 colors but it is not needed for a true-color (24-bit)
display.  In some cases, you may want to turn off dithering since it
causes a grainy output.
    In the dialog box in which you select a file, pressing the "Display"
button will display the file with the chosen display options.  Pressing
the "Preview" button will display the file with 1-pass quantization and
dithering off.  This combination will display an image 25-50% faster than
2-pass quantization with dithering on.
    There are two save options: quality factor and entropy optimization.
The quality factor, an integer between 0 and 100 inclusive, determines
the tradeoff between the output file size and the output image quality.
If you choose a high quality factor, the image quality will be high but
the file size will be large.  A lower quality setting will yield a smaller
file at a cost of lower quality.  Entropy optimization produces a smaller
JPEG file but it takes more time to encode the image; it takes an extra
two passes.


Description of Menu Items
-------------------------

Edit
----
  HSI Adjustment
  --------------
      This option is available for only color-indexed bitmaps(i.e. 8-bit
  bitmaps).  Use the scroll bars to adjust the average amount of hue,
  saturation, and intensity/brightness in an image.

  Color Balance
  -------------
      This option is available for only color-indexed bitmaps.  Use the scroll
  bars to adjust the average amount of red, green, and blue in an image.

  Rotate
  ------
      Rotate the image clockwise by 90 degrees.

  Flip Horizontal
  ---------------
      Flips the image around the vertical axis.

  Flip Vertical
  -------------
      Flips the image around the horizontal axis.

Options
-------
  8-bit Bitmap
  ------------
      When you load an image with this menu item checked, WinJPEG will
  quantize the number of colors to 256, and display the image in an 8-bit
  bitmap.  This feature is available in only Windows display modes that can
  handle more than 256 colors.  An example of an application is to preview
  a JPEG image in an 8-bit bitmap before saving it to a GIF.  However, it is
  not necessary to use this feature to save a 24-bit JPEG into an 8-bit GIF.

  Auto-resize
  -----------
      This menu item allows you to turn on/off the auto-resizing feature.
  When it is enabled, WinJPEG will automatically resize the window so that
  the image will fit just inside the window.  When an image is intially
  loaded, the window size is changed so that the largest possible portion
  of the image is displayed.  When you change the window size so that it is
  larger than the image size, the window will be resized so that it just fits
  around the image.


Registration
------------

    The full version of WinJPEG will be available in the second week of
June.  It may be purchased by completing the order form and mailing the form
and $15 (non-US registrations may have an additional charge) to:

      Norman Yee
      58 Chandler St.
      Boston, MA 02116

    When you register, you will receive WinJPEG v1.00, a user manual, and a
collection of JPEG images(I will put as many as I can fit on 2 720k 3 1/2"
floppies, on 1 1.44M 3 1/2" floppy or on 4 360k 5 1/4" floppies).  Once you
are registered, you will receive upgrades of WinJPEG for free except for a
small charge for the disk and shipping.  If you have a Internet account or
a Compuserve account, you will be e-mailed upgrades for no charge.
    If you have any questions, comments, suggestions, or bug reports, please
feel free to send me e-mail to my Internet account: [e-mail]


Reporting Errors
----------------

    If you encounter a problem with this program, please send in a bug
report.  Please give us a description of the hardware configuration of the
system you are using, what other software was running in the background, what
file you were loading, what the symptoms are, and anything else that might
help us reproduce the problem.


Disclaimer
----------

    The authors of this program accept no responsibility for damages that
are caused by this program and make NO WARRANTY or representation, either
express or implied, with respect to this software.  This software is provided
"AS IS", and you, its user, assume the entire risk when you use it.

WinJPEG is copyright (C) 1992, Norman and Ken Yee.  All rights reserved.



Acknowledgements
----------------

WinJPEG is based in part on the work of the Independent JPEG Group.

The Graphics Interchange Format(c) is the Copyright property of CompuServe
Incorporated.  GIF(sm) is a Service Mark property of CompuServe Incorporated.

GIF2JPG is a trademark of Handmade Software, Inc.