Masking the GIF files?

[Lachie Dazdarian]

How can I mask the GIF files so that they are unreadible by common image viewers but that I can still load them with my QBasic gif loader?

Is this possible? Gif loader is not by me so altering it would be a problem.

[relsoft]

Change the header. ;*)

[Lachie Dazdarian]

Right...

Newsflash: Lachie is a dummy! Dummy needs dummy instructions.

[adosorken]

A technique I used for old WOS betas...

Each tileset was saved as an SBS file (Super BSAVE), and I then wrote a tool to wipe out the palette and save the tileset to GIF. Only WOS could use the GIF...Windows-based viewers and editors, even if you applied a palette with indexing, could never view them because they equated all pixels to 0 due to the plain black palette.

The reason I did that though was so that no one could see the files as they were being loaded. Nowadays, I got my act together and know how to black-out the palette during the GIF load so no one sees the load anyways. :lol:

[Lachie Dazdarian]

And that's not really helping me.

Unless you are saying I load up a black palette and copy and paste all 17 images on new pages with black palettes and save them?

I'm way to lazy to be doing that.

[na_th_an]

You can do what I suggested you a while ago.

GIF files have an ID field in their header. If you examine your GIF loader you'll find it out somewhere. I think it should read GIF87 or GIF89. The trick is modify your loader to check for "KENTA" (for instance) instead of the aforementioned strings. Then you write a program that opens the files and change their headers.

[Lachie Dazdarian]

You mean header as a begining of a file? How do I open GIF files when changeing their header. With a plain text reader? Or with somekind of more complex file reader that can read files in HEX.

[Neo]

Download the best Hex Editor: http://www.bpsoft.com/downloads/
Hex Workshop (not for DOS I think)

[na_th_an]

yeah, but you can also try qb:

Code:

header$="KENTA"
PUT #1, offset%, header$

You only have to find the proper "offset%", the position where the ID is (I think that most likely offset%=1).

[Neo]

Yep, very simple as well.

Take a look: http://www.onicos.com/staff/iz/formats/gif.html