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Looking for a binary read and write .gif file example

Posted on 2002-05-14
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Last Modified: 2011-09-20
I want to be able to read and write a .gif file without using any ocx. Do you know about any example that uses the GIF FORMAT Specifications to Read or Write these files
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Question by:wcoka
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LVL 22

Expert Comment

by:rspahitz
ID: 7009803
I believe that you will need to contact Compuserve since this format is copyrighted and cannot be created without their permission.
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Expert Comment

by:Anthony Perkins
ID: 7009931
rspahitz,

I believe you may be dating yourself here:  I think you mean Unisys, see:
GIF AND OTHER UNISYS LZW LICENSES
http://www.microsoft.com/devonly/unisys.htm

Anthony
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Expert Comment

by:Anthony Perkins
ID: 7009935
Also:
INFO: Unisys GIF and LZW Technology License Information (Q193543)
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q193543&SD=MSKB&

Anthony
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Expert Comment

by:Anthony Perkins
ID: 7009939
wcoka,

Please maintain your open questions:

What values should I use to validate an empy field Date: 10/26/2001 11:04AM PST
http://www.experts-exchange.com/jsp/qShow.jsp?ta=visualbasic&qid=20217546
how to read cell values from an excel file? Date: 10/06/2001 12:21AM PST
http://www.experts-exchange.com/jsp/qShow.jsp?ta=visualbasic&qid=20191560
How to run a Perl Script function from PHP Date: 11/08/2001 06:15PM PST
http://www.experts-exchange.com/jsp/qShow.jsp?ta=php&qid=20229723

Anthony
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by:rspahitz
ID: 7011414
Anthony, I must have missed it.

1) Am I correct that it used to be Compuserve?
2) Did Unisys buy Compuserve, or did it simply acquire the rights to the gif technology?
3) The point is still correct that it's copyrighted technology, right?

I found these items in MS Help, which seem to answer those questions:

1) "Note   The Unisys Corporation has a patent that it alleges covers certain aspects of GIF-LZW compression technology, which the PictureBox and Image controls use. Microsoft Corporation obtained a license to the Unisys LZW patents in September, 1996. Microsoft's license does not, however, extend to software developers or third parties who use any Microsoft toolkit, language development, or operating system products to provide GIF read/write and/or any other LZW capabilities in their own products (for example, by way of DLLs and APIs).

"If your commercial application uses either of these controls (and thus, the LZW technology), you may wish to obtain an independent legal opinion on the effect of the patent, or contact Unisys USA at http://www.unisys.com/ for more information."

2) "GIF (Graphic Interchange Format) is a compressed bitmap format originally developed by CompuServe. It supports up to 256 colors and is a popular file format on the Internet."

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by:Anthony Perkins
ID: 7011745
rspahitz,

I may not have been totally accurate. Here is a link that may be enlightening:
Unisys Clarifies Policy Regarding Patent Use in On-Line Service Offerings
http://lpf.ai.mit.edu/Patents/Gif/unisys.html

Anthony
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by:rspahitz
ID: 7011897
Thanks, Anthony.  I just wish there was a date on that document.  It appears to be from 1995.  

The issue seems to be that Compuserve took Unisys' patented compression technology and embedded it into the GIF specifications, thereby requiring a license in order to create a commercial tool which creates GIF files.

Here are some key excerpts:

"Two years ago, Unisys learned that the LZW method was incorporated in the GIF specification and immediately began negotiations with CompuServe in January of 1993. We reached agreement with CompuServe on licensing the technology in June 1994, which calls for CompuServe to pay Unisys a royalty of 1% of the average selling price it charges for its software. This represents approximately 11 cents for each copy sold and connected to its information service.

"Under the agreement, CompuServe, at its discretion, could relicense the LZW technology to commercial developers using the GIF specification in software that connected directly to the CompuServe information service."

--
"...Unisys expects developers of commercial, for-profit software to secure a license from Unisys, or through the licensed on-line service, for the use of the patented technology...Unisys does not require licensing, or fees to be paid, for non-commercial, non-profit GIF-based applications, including those for use on the on-line services."

--
"...only the software firms who sell the enabling software for profit would be expected to secure a licensing agreement from Unisys."
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Expert Comment

by:rspahitz
ID: 7011915
wcoka,

At this point, I think your best bet it to check the  EE archives as this question has come up on numerous occassions and you will probably find numerous answers.
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Author Comment

by:wcoka
ID: 7016680
But, I dont think I should ask persminio to READ only their format. What I'm working on, is on a GIF to OTA(Nokia graphics) translator.
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Expert Comment

by:rspahitz
ID: 7016748
If all you want is a way to read gif files, use the built-in VB translator.  Load the .gif into a picturebox and it's ready to be saved in any format you conjure up!

Specifically:

Picture1.Picture = LoadPicutre(strMyPathToGIFPicture)
SavePicureInOTAFormat Picture1.Picture
...

private sub SavePicureInOTAFormat(PictureToConvert as Picture)
   ' Write your OTA conversion code here.
end sub
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Author Comment

by:wcoka
ID: 7017118
Two things:

1. How should I read picture1.picture, in what format is it? BMP?

2. For reading gif format images, I dont need to ask permission. So if anyone knows about any example of how to read this format, Id apreciate a lot.

I've found information about the format specifications but I get confused with the LZW compression

Thanks in advance
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Expert Comment

by:rspahitz
ID: 7017144
#1 The picture is in "Picture" format, which is essentiallly pixel format.  BMP is essentially Picture format plus headers.

If you export the Picture, VB will save it in BMP format.

#2 Since it's built into VB, do you really need it?

Here are a few from the EE archives that might help:

Image Manipulation Component
http://www.experts-exchange.com/questions/Q.20116218.html

gif files
http://www.experts-exchange.com/questions/Q.20113067.html

Gif Animation
http://www.experts-exchange.com/questions/Q.20096711.html
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Author Comment

by:wcoka
ID: 7018744
I need to understand how to read gif files so that I can translate them to OTA
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rspahitz earned 199 total points
ID: 7021958
At this point, I would suggest the above links.

I still don't see why you need to directly translate.  Once you have the picture in memory, you have everything you need to start translating into OTA format.
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by:DanRollins
ID: 7765486
Hi wcoka,
It appears that you have forgotten this question. I will ask Community Support to close it unless you finalize it within 7 days. I will ask a Community Support Moderator to:

    Accept rspahitz's comment(s) as an answer.

wcoka, if you think your question was not answered at all or if you need help, just post a new comment here; Community Support will help you.  DO NOT accept this comment as an answer.

EXPERTS: If you disagree with that recommendation, please post an explanatory comment.
==========
DanRollins -- EE database cleanup volunteer
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by:SpideyMod
ID: 7838127
per recommendation

SpideyMod
Community Support Moderator @Experts Exchange
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