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Posted: **Sun May 18, 2008 7:41 pm**

Hi,

How I do to detect a bitmap format (16bpp/32bpp) *after* I'd loaded it please?

Thanks and regards,

Toninho.

Posted: **Mon May 19, 2008 8:17 am**

Toninho,

here you have a function to read all properties of a bitmap

#define TAB Chr(9)

...
nH := FOpen (cBmp)
MsgInfo (BmpInfo (nH)
FClose (nH)
...

//-------------------------------------------------------------------//
FUNCTION BmpInfo (nH, cBmp)

  LOCAL i, cInfo := ""
  LOCAL aInfoText := {"Bitmaptype"+TAB+": ",;//       : ",;
                      "Size"+TAB+TAB+": ",;//             : ",;
                      "reserved"+TAB+TAB+": ",;//         :",;
                      "reserved"+TAB+TAB+": ",;//         :",;
                      "Data offset"+TAB+": ",;//      : ",;
                      "Header Size"+TAB+": ",;//      : ",;
                      "Width"+TAB+TAB+": ",;//            : ",;
                      "Height"+TAB+TAB+": ",;//           : ",;
                      "No planes"+TAB+": ",;//        : ",;
                      "Bits/pixel"+TAB+TAB+": ",;//       : ",;
                      "Compression"+TAB+": ",;//      : ",;
                      "Image Data size"+TAB+": ",;//  : ",;
                      "horz. pixel/meter"+TAB+": ",;//: ",;
                      "Vert. pixel/meter"+TAB+": ",;//: ",;
                      "No of colors"+TAB+": ",;//     : ",;
                      "Important colors"+TAB+": "  }

  aInfo := Array (20)

  IF nH > 0

    aInfo[1] := Chr (FReadByte (nH, 0, 1)) +;   // Typ
                Chr (FReadByte (nH, 1, 1))
    aInfo[2] := FReadByte (nH, 2,4)    // Filesize
    aInfo[3] := FReadByte (nH, 6,2)    // reserved, 0
    aInfo[4] := FReadByte (nH, 8,2)
    aInfo[5] := FReadByte (nH, 10,4)   // Data offset
    aInfo[6] := FReadByte (nH, 14,4)    // size of BitmapInfoHeader
    aInfo[7] := FReadByte (nH, 18,4)    // width
    aInfo[8] := FReadByte (nH, 22,4)    // height
    aInfo[9] := FReadByte (nH, 26,2)    // no of planes, must be 0
    aInfo[10] := FReadByte (nH, 28,2)   // no of bits / pixel
    aInfo[11] := FReadByte (nH, 30,4)   // compression type
    aInfo[12] := FReadByte (nH, 34,4)   // size of image dat in bytes, 0 when no compression
    aInfo[13] := FReadByte (nH, 38,4)   // horz. pixel / meter
    aInfo[14] := FReadByte (nH, 44,4)   // vert. pixerl / meter
    aInfo[15] := FReadByte (nH, 46,4)   // no of colors
    aInfo[16] := FReadByte (nH, 50,4)   // no of important colors
    //aInfo{17] := FReadByte (nH, 54,4)   //

    cInfo := cBmp+CRLF
    FOR i := 1 TO 16
      cInfo += aInfoText[i]+cValToChar (aInfo[i])+CRLF
    NEXT

  ENDIF

RETURN (cInfo)



//-------------------------------------------------------------------//
FUNCTION FReadByte (nH, nOffset, nLen, lHex)

  LOCAL i, cBuffer, xByte, nByte

  DEFAULT lHex := .f.  // return hex numbers

  FSeek (nH, nOffset, 0)
  cBuffer := Space (nLen)
  FRead (nH, @cBuffer, nLen)
  IF nLen = 4  // 32 bit
    nByte := Bin2L (cBuffer)
  ELSE
    nByte := Bin2I (cBuffer)
  ENDIF

  xByte := IIF (!lHex, nByte, Lower (DecToHex (nByte)) )
  IF lHex
    IF Len(xByte)<2
      xByte := "0"+xByte
    ENDIF
  ENDIF
  //? cByte, DecToHex (nByte), Len(cByte), Empty(cByte)

RETURN (xByte)

Posted: **Mon May 19, 2008 11:09 am**

Stefan, thanks for your help. Do you know if there are any way to use bitmap handle? Something like: GetBitmapFormat( oBmp:hBitmap ) ?

Regards,

Toninho.

Posted: **Mon May 19, 2008 12:00 pm**

Toninho,

Try this:

Code: Select all

HB_FUNC( BMPFORMAT ) // hBitmap --> nBitsPixel
{
   BITMAP bm;

   GetObject( ( HBITMAP ) hb_parnl( 1 ), sizeof( BITMAP ), ( LPSTR ) &bm );

   hb_retnl( bm.bmBitsPixel );
}

Posted: **Mon May 19, 2008 12:36 pm**

Antonio Linares wrote:Toninho,

Try this:

Code: Select all

HB_FUNC( BMPFORMAT ) // hBitmap --> nBitsPixel
{
   BITMAP bm;

   GetObject( ( HBITMAP ) hb_parnl( 1 ), sizeof( BITMAP ), ( LPSTR ) &bm );

   hb_retnl( bm.bmBitsPixel );
}

Thanks Antonio, but this is the first thing that I´d tried and the bm.bmBitsPixel always return 32. If I go to the proprierties of the .bmp file in windows, I see 8 bits.

Maybe is because I load it by Resource ?

Very strange.

Regards,

Toninho.

Posted: **Tue May 20, 2008 7:37 am**

toninhofwi wrote:Stefan, thanks for your help. Do you know if there are any way to use bitmap handle? Something like: GetBitmapFormat( oBmp:hBitmap ) ?

No, sorry. If Antonios function does not work, I have no solution.

Posted: **Tue May 20, 2008 10:47 am**

Toninho,

Maybe we could try to check these struct members:

typedef struct tagBITMAPINFOHEADER{ // bmih
DWORD biSize;
LONG biWidth;
LONG biHeight;
WORD biPlanes;
WORD biBitCount;
DWORD biCompression;
DWORD biSizeImage;
LONG biXPelsPerMeter;
LONG biYPelsPerMeter;
DWORD biClrUsed;
DWORD biClrImportant;
} BITMAPINFOHEADER;

Posted: **Tue May 20, 2008 11:47 am**

Antonio Linares wrote:Toninho,
Maybe we could try to check these struct members:

Thanks Antonio.

Is very strange but for loaded file images biBitCount works but for loaded *resources* it always return 32. I solve my problem create a new parameter for DEFINE BITMAP command, that now have a new option: ALPHABLEND.

---cut---
#xcommand REDEFINE BITMAP [ <oBmp> ] ;
[ ID <nId> ] ;
[ <of: OF, WINDOW, DIALOG> <oWnd> ] ;
[ <resource: NAME, RESNAME, RESOURCE> <cResName> ] ;
[ <file: FILE, FILENAME, DISK> <cBmpFile> ] ;
[ <lClick: ON ClICK, ON LEFT CLICK> <uLClick> ] ;
[ <rClick: ON RIGHT CLICK> <uRClick> ] ;
[ <scroll: SCROLL> ] ;
[ <adjust: ADJUST> ] ;
[ CURSOR <oCursor> ] ;
[ MESSAGE <cMsg> ] ;
[ <update: UPDATE> ] ;
[ WHEN <uWhen> ] ;
[ VALID <uValid> ] ;
[ <transparent: TRANSPARENT> ] ;
[ <alphablend: ALPHABLEND> ] ;
=> ;
[ <oBmp> := ] TBitmap():ReDefine( <nId>, <cResName>, <cBmpFile>,;
<oWnd>, [\{ |nRow,nCol,nKeyFlags| <uLClick> \}],;
[\{ |nRow,nCol,nKeyFlags| <uRClick> \}],;
<.scroll.>, <.adjust.>, <oCursor>, <cMsg>, <.update.>,;
<{uWhen}>, <{uValid}>, <.transparent.>, <.alphablend.> )
--cut---

Thanks and best regards.

PS: I only have problems now painting alphablended bitmaps in grayscale. Please see another topic that I´d created.

Posted: **Tue May 20, 2008 11:51 am**

Toninho,

I see. Yes, its a good idea to add it for Class TBitmap, thanks!

Posted: **Tue May 20, 2008 2:09 pm**

I had a question in a topic a few days ago, about to swich from
alphablend to 'normal' BMP.
Would it be possible to have this solution with this extra parameter ?

Another idea was for the function :

Sample :
ABPaint( hDC, 5, 5, oBmp:hBitmap, 255 )

// Value 0-255 use < 0 > for non alpablended Bitmaps ?
// only 1 Function for the different Bitmap-types

ABPaint( hDC, 5, 5, oBmp:hBitmap, 0 )

Regards

Uwe

Posted: **Tue May 20, 2008 2:22 pm**

Uwe,

Yes, this new clause will help us to select the right paint function to be called from Class TBitmap Method Paint()

Posted: **Wed May 21, 2008 5:44 am**

Toninho,

I guess that what we really need is a way to programmatically detect if a bitmap has an alpha channel.

We are looking to build such function.

Posted: **Wed May 21, 2008 6:37 am**

Toninho,

Well it seems that we go back to the first function

Code: Select all

HB_FUNC( BMPALPHA ) // hBitmap --> lYesNo 
{ 
   BITMAP bm; 

   GetObject( ( HBITMAP ) hb_parnl( 1 ), sizeof( BITMAP ), ( LPSTR ) &bm ); 

   hb_retl( bm.bmBitsPixel == 32 ); 
}

But, do you say that all bitmaps return .T. ?

Posted: **Wed May 21, 2008 6:41 am**

> But, do you say that all bitmaps return .T. ?

I answer myself: yes. Bitmaps without alpha channel are returning .T. also, and I am using DEFINE BITMAP ... FILENAME ...

We need to find another way to check it

FiveTech Software tech support forums

Howto Detect Bitmap Format

Howto Detect Bitmap Format

Switch from 'normal' BMP to ALPHABLEND