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gif2png 2.3.2 - Macintosh version 1.0

Macintosh version by Hide Itoh
Please see the Copyright & Acknowledgement section at the end of this document.

Introduction - What is gif2png ?

gif2png is a small utility program that converts GIF files into PNG files. The original UNIX version of gif2png was created by Eric S. Raymond. This Macintosh version is developed based on the original UNIX version of gif2png and I have created a kind of wrapper for Macintosh that makes the look and feel of gif2png like other Macintosh programs. I tried to minimize the modification of original gif2png source code. Like original gif2png, Macintosh version also uses libpng and zlib as the core library. libpng 1.0.8 was ported to Mac OS by myself and zlib 1.1.3 was ported to Mac OS by Jack Jansen.


iMacolor requires Mac OS 8.0 or later. No hardware requirements (you can use it with both 68K and PPC models).

Besides, you may be able to use with System 7.1 and later if the Appearance Manager 1.02 or later is installed. However, please understand that I have not tested under such environment since I do not have such computer environment.


No special installation required. Just like any other application program, place it somewhere on your computer's hard disk drive. Since gif2png write back some data into it's resources, you can not use gif2png on write-protected media like CD-ROM. I recommend that you place gif2png on desktop or your launcher because the most popular way of using gif2png is to use drag & drop interface (like StuffIt Expander)

Using gif2png

It's pretty easy to use gif2png. All you need to do is just drag & drop GIF files you want to convert to PNG files on the gif2png's application icon under Finder. You may drag and drop folders that has some GIF files to convert all of them too. If the folder you drop includes non-GIF files, gif2png does not touch them at all.

Another way to use gif2png is just start the gif2png by double-clicking the application icon. Then choose
Convert... menu item from the File menu. Then select a GIF file you want to convert. With this method, you can not convert multiple GIF files/folders. Only a single file can be converted at a time.

After the conversion is done, gif2png display the conversion log (report) to the screen. You can save the log as a text file if you want to keep it.


Since Macintosh program does not take command line arguments, I put most of the options of original gif2png, plus some Macintosh version specific options into Preferences dialog. To access the Preferences dialog, double-click the application icon and start gif2png. Then choose Preferences... menu item from the File menu.

The first group is Macintosh specific settings. You can specify the type/creator of output PNG file. By default, it uses the creator for Adobe Photoshop. Although you can change the PNG file name extension, I recommend that you use either
.png or .PNG.

The four options from the top of the next option group are also Macintosh specific options. All the other options are from the original gif2png.

Recursively convert entire directories
By default, if a folder is drag & dropped, gif2png convert all GIF files directory under the folder. All the GIF files in sub folder of the folder are not converted. If you want to convert all GIF files in entire directory(folder) tree, check this option.

Do not convert transparent GIF files (web safe)
Since some browser has problem of showing transparent PNG file (like Netscape Navigator 4.0-4.7), you may not want to replace transparent GIF files into PNG files. If so, check this option. gif2png will not touch transparent GIF files if this option is selected.

Do not convert animation GIF files (web safe)
Due to the design and spec. of PNG, it can not contain multiple images in one PNG file. Therefore, if you convert an animation GIF file, gif2png convert it into multiple PNG files. If you don't like this, check this option. Then gif2png will not touch animation GIF files.

Verbose level
After the conversion is done, gif2png show the conversion result log on screen. Default verbose level is 2.
0 - No log and it suppress the conversion log display.
1 - Displays file names that has been processed.
2 - Displays basic image info like image size and number of color used in additon to 1.
3 - Displays more detail information like RGB color pallette values in addition to 2.

Other options are for power users and those who are familiar with graphic file format. Leave these options as it is if you don't know what it means.

Important Note

About file name
Due to some internal reasons, Macintosh version can not handle full path name which is more than 255 character length.

Also based on the spec of original gif2png, output file name is determined by the rules below:

If the original GIF file name contain either one of .gif, .GIF, _gif, _GIF, then the part before such extension is used as the base and PNG file name extension is appended to the base name. If original GIF file name uses any other extension, it will replace the extension with PNG extension.

Therefore, "sample.gif copy" will be converted to "sample.png" (not "sample.png copy"), and "sample.gif.2" will be converted to "sample.gif.png" (not "sample.gif.2").

In most case you don't have to worry this behavior since most people name their GIF file like xxxxxx.gif.

Macintosh version overwrite the existing file if the same output PNG file name already exists.

Version-up History

1.0 Aug 26, 2000
Original Macintosh version (based on gif2png 2.3.2, libpng 1.0.8 and zlib 1.1.3)

Freeware distribution

You can distribute it free via electronic bulletin boards, user groups, and person to person. When distributed, all accompanying files (the Read Me document, the program, etc.), are to distributed with the software without exception. Please do not modify the original document and software. The software is not to be included with any commercial software or any public domain/shareware package sold for profit without proper written consent from the author.


While the author of this software has made every effort to deliver a high quality product, the author does not guarantee that this product is free from defects. The author is not responsible for any damage to the purchaser's computer system or data and in no event will I be responsible to the purchaser for any consequential, incidental, or indirect damages (including but not limited to damages for loss of business profits, business interruption, or loss of data) arising out of the use or inability to use this product, even if I have been advised of the possibility of such damages. Because some states do not allow the exclusion or limitation of liability for consequential or incidental damages, the above limitations may not apply to you. The use of this software includes the complete agreement of this disclaimer.

Copyright and Acknowledgement

gif2png Macintosh version

Copyright (C) 2000 Hide Itoh . All rights reserved.

gif2png original unix version
Original code by Alexander Lehmann
Auto-interlaceq and tRNS optimization by Greg Roelofs .
Manual page and production packaging by Eric S. Raymond .
Copyright (C) 1999 Eric S. Raymond
The file gifread.c is also Copyright (C) 1990-1994 by David Koblas.

libpng 1.0.8
Copyright (c) 2000 Glenn Randers-Pehrson
Contributed Authors: Simon-Pierre Cadieux, Eric S. Raymond, Gilles Vollant
Official PNG and linpng web site:
Macintosh port by Hide Itoh

zlib 1.1.3
Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler
Official zlib web site:
Macintosh port by Jack Jansen

Special thanks to all the people who has contributed to the development of gif2png, libpng and zlib.

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