Re: [Libpgf-user] sample pgf files

[Phil H. <ph...@ow...>]

Hi Raphael,

Thanks for explaining this, and for the sample images.

I got the 768-byte colour table size from the exiv2 0.21 source code  
since I didn't have any indexed colour samples to test, but it seems  
as if it might be exiv2 with the problem here.

	- Phil


On 7-Mar-11, at 9:30 AM, Schweizer Raphael wrote:

> Hi Phil
>
> Glad to hear about the upcomming support of PGF in ExifTool.
>
> "There is a question of version number if we go to software other  
> than digikam.  Currently digikam writes a version of 0x36 and it  
> seems that this version may use a 768-byte indexed color table,  
> which is different from the 1024-byte table mentioned in the PGF  
> specification (which is for version 6, but it is unclear to me if  
> version 6 is hexadecimal 0x06, or ASCII "6" in the header as  
> written by digikam.)"
>
> The current file format is 6, 0x36 as written by digiKam through  
> libPGF originates from a 'version mask' (from PGFtypes.h):
>
> // version flags
> #define Version2			2					// data structure PGFHeader of major  
> version 2
> #ifdef __PGF32SUPPORT__
> #define PGF32				4					// 32 bit values are used -> allows at  
> maximum 31 bits
> #else
> #define PGF32				0					// 16 bit values are used -> allows at  
> maximum 15 bits
> #endif
> #define PGFROI			8					// supports Regions Of Interest
> #define Version5			16					// new coding scheme since major version 5
> #define Version6			32					// new HeaderSize: 32 bits instead of 16  
> bits
> // version numbers
> #define PGFVersion			(Version2 | Version5 | Version6 | PGF32)	//  
> current standard version
>
> The size of the (optional, only used for indexed images) color  
> table is always 1024 bytes. If we write otherwise, please leave a  
> message so we can correct that. A current no-user-data PGF file  
> will start with "50 47 46 36" followed by "10 00 00 00" (16 decimal  
> = 0x10 bytes) for non-indexed respectively "10 04 00 00" (1040 = 16  
> + 1024 decimal = 0x410 bytes)  for indexed images.
>
> I attached some sample files containing no user data. Feel free to  
> ask any follow up questions.
>
> - Raphael
>
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> <Bitmap1.PGF><Indexed8.PGF><RGB12.PGF><RGB32.PGF><Gray8.PGF>