compress algorithm for BLOB

Recently I want to grab picture for nav Database. But it has been compressed by certain algorithm. I tried Zip and Deflate. But I failed. Anybody knows what algorithm Nav uses? Or is there some other appoaches that I can grab from Nav database from outside of Nav.



Disable BLOB compression in field properties.

Is there some other approach to get that? My boss don’t want to turn off the compress attribute. I wrote a small software to do the compress and decompress. It works.but because I don’t know the algorithm, I cannot decompress.

Two approaches come to mind:

  1. Use web-services to access a NAV codeunit. Make that codeunit generically take a table no., field no. to reference a blob field. Then have it write the blob field, as text to the filesystem. The text will be decompressed.

  2. You may be able to use C-Front to decompress the data.

NAV is using a fairly old custom algorithm similar to that employed by PKARK if you remember that.

Since its custom you won’t be able to de-compress it.

Going with C/Front or C/Front .Net, as girish suggessted, is a good solution.

Thanks a lot!