[This is preliminary documentation and subject to change.]
The BITMAPV5HEADER structure is the Windows NT 5.0 and Windows 98 bitmap information header file. The Independent Color Management interface (ICM) 2.0 allows International Color Consortium (ICC) color profiles to be linked or embedded in device-independent bitmaps (DIBs). See Using Structures in ICM 2.0 for more information.
Applications written for Windows NT 4.0 and Windows 95 can use the BITMAPV4HEADER structure. Applications written for earlier versions of Windows NT should continue to use the BITMAPINFOHEADER structure.
The BITMAPV5HEADER is an extended version of BITMAPINFOHEADER that allows a JPEG image to be passed as the source image to StretchDIBits.
typedef struct {
DWORD bV5Size;
LONG bV5Width;
LONG bV5Height;
WORD bV5Planes;
WORD bV5BitCount;
DWORD bV5Compression;
DWORD bV5SizeImage;
LONG bV5XPelsPerMeter;
LONG bV5YPelsPerMeter;
DWORD bV5ClrUsed;
DWORD bV5ClrImportant;
DWORD bV5RedMask;
DWORD bV5GreenMask;
DWORD bV5BlueMask;
DWORD bV5AlphaMask;
DWORD bV5CSType;
CIEXYZTRIPLE bV5Endpoints;
DWORD bV5GammaRed;
DWORD bV5GammaGreen;
DWORD bV5GammaBlue;
DWORD bV5Intent;
DWORD bV5ProfileData;
DWORD bV5ProfileSize;
DWORD bV5Reserved;
} BITMAPV5HEADER, FAR *LPBITMAPV5HEADER, *PBITMAPV5HEADER;
#define BI_JPEG 4L
Windows 98, Windows NT 5.0 and later: If bV5Compression is BI_JPEG, the bV5Width member specifies the width of the decompressed JPEG image in pixels.
If bV5Height is negative, indicating a top-down DIB, bV5Compression must be either BI_RGB or BI_BITFIELDS. Top-down DIBs cannot be compressed.
Windows 98, Windows NT 5.0 and later: If bV5Compression is BI_JPEG, the bV5Height member specifies the height of the decompressed JPEG image in pixels.
This member can be one of the following values.
| Value | Meaning |
|---|---|
| 0 | Windows 98, Windows NT 5.0 and later: The number of bits per pixel is specified or is implied by the JPEG file format. |
| 1 | The bitmap is monochrome, and the bmiColors member contains two entries. Each bit in the bitmap array represents a pixel. If the bit is clear, the pixel is displayed with the color of the first entry in the bmiColors color table. If the bit is set, the pixel has the color of the second entry in the table. |
| 4 | The bitmap has a maximum of 16 colors, and the bmiColors member contains up to 16 entries. Each pixel in the bitmap is represented by a 4-bit index into the color table. For example, if the first byte in the bitmap is 0x1F, the byte represents two pixels. The first pixel contains the color in the second table entry, and the second pixel contains the color in the sixteenth table entry. |
| 8 | The bitmap has a maximum of 256 colors, and the bmiColors member contains up to 256 entries. In this case, each byte in the array represents a single pixel. |
| 16 | The bitmap has a maximum of 2^16 colors. If the biCompression member of the BITMAPV5HEADER structure is BI_RGB, the bmiColors member is NULL. Each WORD in the bitmap array represents a single pixel. The relative intensities of red, green, and blue are represented with 5 bits for each color component. The value for blue is in the least significant 5 bits, followed by 5 bits each for green and red. The most significant bit is not used. The bmiColors color table is used for optimizing colors used on palette-based devices, and must contain the number of entries specified by the biClrUsed member of the BITMAPV5HEADER. If the biCompression member of the BITMAPV5HEADER is BI_BITFIELDS, the bmiColors member contains three DWORD color masks that specify the red, green, and blue components, respectively, of each pixel. Each WORD in the bitmap array represents a single pixel. When the biCompression member is BI_BITFIELDS, bits set in each DWORD mask must be contiguous and should not overlap the bits of another mask. All the bits in the pixel do not need to be used. |
| 24 | The bitmap has a maximum of 2^24 colors, and the bmiColors member is NULL. Each 3-byte triplet in the bitmap array represents the relative intensities of blue, green, and red, respectively, for a pixel. The bmiColors color table is used for optimizing colors used on palette-based devices, and must contain the number of entries specified by the biClrUsed member of the BITMAPV5HEADER structure. |
| 32 | The bitmap has a maximum of 2^32 colors. If the biCompression member of the BITMAPV5HEADER is BI_RGB, the bmiColors member is NULL. Each DWORD in the bitmap array represents the relative intensities of blue, green, and red, respectively, for a pixel. The high byte in each DWORD is not used. The bmiColors color table is used for optimizing colors used on palette-based devices, and must contain the number of entries specified by the biClrUsed member of the BITMAPV5HEADER. If the biCompression member of the BITMAPV5HEADER is BI_BITFIELDS, the bmiColors member contains three DWORD color masks that specify the red, green, and blue components of each pixel. Each DWORD in the bitmap array represents a single pixel. |
| Value | Meaning |
|---|---|
| BI_RGB | An uncompressed format. |
| BI_RLE8 | A run-length encoded (RLE) format for bitmaps with 8 bits per pixel. The compression format is a two-byte format consisting of a count byte followed by a byte containing a color index. If bV5Compression is BI_RGB and the bV5BitCount member is 16, 24, or 32, the bitmap array specifies the actual intensities of blue, green, and red rather than using color table indexes. For more information, see Bitmap Compression. |
| BI_RLE4 | An RLE format for bitmaps with 4 bits-per-pixel. The compression format is a two-byte format consisting of a count byte followed by two word-length color indexes. For more information, see Bitmap Compression. |
| BI_BITFIELDS | Specifies that the bitmap is not compressed and that the color table consists of three DWORD color masks that specify the red, green, and blue components of each pixel. Valid when used with 16- and 32-bit-per-pixel bitmaps. |
| BI_JPEG | Windows 98, Windows NT 5.0 and later: Specifies that the image is compressed using the JPEG file Interchange Format. JPEG compression trades off compression against loss; it can achieve a compression ratio of 20:1 with little noticeable loss. |
Windows 98, Windows NT 5.0 and later: If bV5Compression is BI_JPEG, bVSizeImage is the size of the JPEG image buffer.
If bV5ClrUsed is nonzero and bV5iBitCount is less than 16, the bV5ClrUsed member specifies the actual number of colors the graphics engine or device driver accesses. If bV5BitCount is 16 or greater, the bV5ClrUsed member specifies the size of the color table used to optimize performance of the system color palettes. If bV5BitCount equals 16 or 32, the optimal color palette starts immediately following the BITMAPV5HEADER. If BV5ClrUsed is nonzero, the color table is used on palettized devices, and bV5ClrUsed specifies the number of entries.
When the bitmap array immediately follows the BITMAPINFO header, it is a packed bitmap. Packed bitmaps are referenced by a single pointer. Packed bitmaps require that the bV4ClrUsed member must be either zero or the actual size of the color table.
The following table specifies the values for bV5CSType.
| Value | Meaning |
|---|---|
| LCS_CALIBRATED_RGB | This value implies that endpoints and gamma values are given in the appropriate fields. |
| LCS_sRGB | Specifies that the bitmap is in sRGB color space. |
| LCS_WINDOWS_COLOR_SPACE | This value indicates that the bitmap is in the system default color space, sRGB. |
| PROFILE_LINKED | This value indicates that bV5ProfileData points to the file name of the profile to use (gamma and endpoints values are ignored). |
| PROFILE_EMBEDDED | This value indicates that bV5ProfileData points to a memory buffer that contains the profile to be used (gamma and endpoints values are ignored). |
See the LOGCOLORSPACE structure for information that defines a logical color space.
The BITMAPINFO structure combines the BITMAPV5HEADER structure and a color table to provide a complete definition of the dimensions and colors of a DIB. For more information about DIBs, see Device-Independent Bitmaps and BITMAPINFO.
An application should use the information stored in the bV5Size member to locate the color table in a BITMAPINFO structure, as follows:
pColor = ((LPSTR)pBitmapInfo +
(WORD)(pBitmapInfo->bmiHeader.biSize));
If bV5Height is negative, indicating a top-down DIB, bV5Compression must be either BI_RGB or BI_BITFIELDS. Top-down DIBs cannot be compressed.
When a DIB is loaded into memory, the profile data (if present) should follow the color table, and the bV5ProfileData should provide the offset of the profile data from the beginning of the BITMAPV5HEADER structure. The value stored in bV5ProfileDate will be different from the value returned by the sizeof operator given the BITMAPV5HEADER argument, because bV5ProfileData is the offset in bytes from the beginning of the BITMAPV5HEADER structure to the start of the profile data. (Bitmap bits do not follow the color table in memory). Applications should modify the bV5ProfileData member after loading the DIB into memory.
For packed DIBs, the profile data should follow the bitmap bits similar to the file format. The bV5ProfileData member should still give the offset of the profile data from the beginning of the BITMAPV5HEADER.
Applications should access the profile data only when bV5Size equals the size of the BITMAPB5HEADER and bV5CSType equals PROFILE_EMBEDDED or PROFILE_LINKED.
If a profile is linked, the path of the profile can be any fully qualified name (including a network path) that can be opened using the CreateFile function.
Windows NT: Requires version 5.0 or later.
Windows: Requires Windows 98 or later.
Windows CE: Unsupported.
Header: Declared in wingdi.h.
Bitmaps Overview, Bitmap Structures