Specifies the number of bits per pixel.The biBitCount member of the BITMAPINFOHEADER
structure determines the number of bits that define each pixel and the maximum number of
colors in the bitmap. This member must be one of the following values.
Namespace:
FreeImageAPI| Value | Meaning |
|---|---|
| 0 | Windows 98/Me, Windows 2000/XP: The number of bits-per-pixel is specified or is implied by the JPEG or PNG format. |
| 1 | The bitmap is monochrome, and the bmiColors member of BITMAPINFO 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 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 of BITMAPINFO 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 of BITMAPINFO 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 BITMAPINFOHEADER is BI_RGB, the bmiColors member of BITMAPINFO is NULL. Each WORD in the bitmap array represents a single pixel. The relative intensities of red, green, and blue are represented with five bits for each color component. The value for blue is in the least significant five bits, followed by five 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 BITMAPINFOHEADER. If the biCompression member of the BITMAPINFOHEADER 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. Windows NT/Windows 2000/XP: 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 have to be used. Windows 95/98/Me: When the biCompression member is BI_BITFIELDS, the system supports only the following 16bpp color masks: A 5-5-5 16-bit image, where the blue mask is 0x001F, the green mask is 0x03E0, and the red mask is 0x7C00; and a 5-6-5 16-bit image, where the blue mask is 0x001F, the green mask is 0x07E0, and the red mask is 0xF800. |
| 24 | The bitmap has a maximum of 2^24 colors, and the bmiColors member of BITMAPINFO 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 BITMAPINFOHEADER. |
| 32 | The bitmap has a maximum of 2^32 colors. If the biCompression member of the BITMAPINFOHEADER is BI_RGB, the bmiColors member of BITMAPINFO 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 BITMAPINFOHEADER. If the biCompression member of the BITMAPINFOHEADER is BI_BITFIELDS, the bmiColors member contains three DWORD color masks that specify the red, green, and blue components, respectively, of each pixel. Each DWORD in the bitmap array represents a single pixel. Windows NT/ 2000: 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. Windows 95/98/Me: When the biCompression member is BI_BITFIELDS, the system supports only the following 32-bpp color mask: The blue mask is 0x000000FF, the green mask is 0x0000FF00, and the red mask is 0x00FF0000. |
Assembly: FreeImageNET (in FreeImageNET.dll)
Syntax
| C# |
|---|
public ushort biBitCount |
| Visual Basic (Declaration) |
|---|
Public biBitCount As UShort |
| Visual C++ |
|---|
public: unsigned short biBitCount |
