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Ernesto Rod
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 Posted: Fri May 27, 2005 5:10 am Post subject: Prefix in Image (Hex Image) |
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Hi:
I'm using the method supply by Remy Lebeau (TeamB):
const char* hex_chars = "0123456789ABCDEF";
AnsiString __fastcall MemStreamToHex(TMemoryStream *pms)
{
AnsiString Result;
int size = pms->Size;
if( size > 0 )
{
Result.SetLength(size * 2);
BYTE *src = (BYTE*) pms->Memory;
char *dest = Result.c_str();
for(int i = 0, j = 0; i < size; ++i)
{
dest[j++] = hex_chars[(src[i] &0xF0) >> 4];
dest[j++] = hex_chars[src[i] & 0x0F];
}
}
return Result;
}
to convert the image to hex and this is working.
Also, I get the same image using:
TComponent* c;
c = Form1->Image1;
pms1->WriteComponent(c);
pms1->Seek(0, soFromBeginning);
ObjectBinaryToText(pms1, pss);
pss->Seek(0, soFromBeginning);
ass = pss->DataString;
and the hex information is not the same:
In the first case I get:
FFD8FFE000104....
but in the second case I get:
Picture.Data = {0A544A504547496D61676570160000FFD8FFE00010.....
The problem is that in the second case there is a prefix "0A544A504547496D61676570160000" of 30 chars (15 Hex). What is this prefix with the same length (30)?
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Vladimir Stefanovic
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| Posted: Fri May 27, 2005 6:14 am Post subject: Re: Prefix in Image (Hex Image) |
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| Quote: | The problem is that in the second case there is a prefix "0A544A504547496D61676570160000" of 30 chars (15 Hex). What is this prefix with the same length (30)?
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It's obviously a 'system' text describing the picture format.
If you exclude first byte (OA) and the last two bytes (0000),
the rest of the bytes interpreted as ASCII means:
TJPEGImagep
Best regards,
Vladimir Stefanovic
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Vladimir Stefanovic
Guest
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| Posted: Fri May 27, 2005 9:31 am Post subject: Re: Prefix in Image (Hex Image) |
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| Quote: | If you exclude first byte (OA) and the last two bytes (0000),
the rest of the bytes interpreted as ASCII means:
TJPEGImagep
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Correction:
[...] and the last three bytes (160000),
the rest of the bytes interpreted as ASCII means:
TJPEGImage
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Remy Lebeau (TeamB)
Guest
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| Posted: Fri May 27, 2005 5:16 pm Post subject: Re: Prefix in Image (Hex Image) |
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"Ernesto Rod" <enriquevald (AT) yahoo (DOT) com> wrote
| Quote: | What is this prefix with the same length (30)?
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1 BYTE, Length of Class Name (0A = 10)
n BYTES, Class Name (544A504547496D616765 = "TJPEGImage")
Remaining BYTES, Class-specific data
The block of data after the class name is specific to TJPEGImage, and the
contains are unknown because Borland does not provide the source code for
TJPEGImage, so I cannot tell you what they are.
Gambit
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Remy Lebeau (TeamB)
Guest
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| Posted: Fri May 27, 2005 5:16 pm Post subject: Re: Prefix in Image (Hex Image) |
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"Vladimir Stefanovic" <antivari (AT) po (DOT) sbb.co.yu> wrote
| Quote: | It's obviously a 'system' text describing the picture format.
If you exclude first byte (OA) and the last two bytes (0000),
the rest of the bytes interpreted as ASCII means:
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See my other reply.
Gambit
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