This reference page is linked to from the following overview topics: High Dynamic Range Bitmaps.
Detailed Description
- See also:
- Class Color.
- Remarks:
- This structure is available in release 4.0 and later
only.
This structure is a 32 bit pixel format that stores 1 bit for sign, 15 bits for the log of the luminance, and 16 bits of chroma.
This class stores colors in XYZ space. XYZ color space is the space define by the CIE by the red (X), green (Y) and blue (Z) response curves of the eye. So to calculate a color in XYZ space, you take the incoming light, multiply it by each response curvey and integrate the result over the visible spectrum. There are several RGB spaces, all depending on what XYZ coordinates get assigned to the red, green and blue primaries of the space. The transformations between XYZ and RGB space are all linear and can be represented as 3 by 3 matrices.
The mapping used by XYZtoRGB and RGBtoXYZ is for CCIR-709 primaries and was taken from the code in the tiff reader for the LogLUV32 format. Both XYZ and RGB methods are supplied, so developers can supply different XYZ to RGB transforms, if desired.
This transform is important, because in the LogLUV32 format the log is taken of the Y coordinate in XYZ space. So, it is important that Y not be 0. The transform helps guarantee this. In fact, Y is zero only when r, g and b are all 0.
#include <color.h>
Inheritance diagram for LogLUV32Pixel:
Public Member Functions |
|
| operator Color () const | |
| LogLUV32Pixel & | operator= (const float c[3]) |
| GEOMEXPORT void | GetRGB (float rgb[3]) const |
| GEOMEXPORT void | SetRGB (const float rgb[3]) |
| GEOMEXPORT void | GetXYZ (float xyz[3]) const |
| GEOMEXPORT void | SetXYZ (const float xyz[3]) |
Static Public Member Functions |
|
| static GEOMEXPORT void | XYZtoRGB (const float xyz[3], float rgb[3]) |
| static GEOMEXPORT void | RGBtoXYZ (const float rgb[3], float xyz[3]) |
Public Attributes |
|
| DWORD32 | value |
| Storage for the pixel value. |
|
Member Function Documentation
| operator Color | ( | ) | const [inline] |
| LogLUV32Pixel& operator= | ( | const float | c[3] | ) | [inline] |
- Remarks:
- Assignment operator.
- Parameters:
- const float c[3]
The array of color values to assign in RGB order.
{ SetRGB(c); return *this; }
| GEOMEXPORT void GetRGB | ( | float | rgb[3] | ) | const |
- Remarks:
- Retrieves the RGB space values.
- Parameters:
- float rgb[3]
The results are stored here.
| GEOMEXPORT void SetRGB | ( | const float | rgb[3] | ) |
- Remarks:
- Sets the RGB space values.
- Parameters:
- const float rgb[3]
The values to set.
| GEOMEXPORT void GetXYZ | ( | float | xyz[3] | ) | const |
- Remarks:
- Retrieves the XYZ space values.
- Parameters:
- const float xyz[3]
The results are stored here.
| GEOMEXPORT void SetXYZ | ( | const float | xyz[3] | ) |
- Remarks:
- Sets the XYZ space values.
- Parameters:
- const float xyz[3]
The values to set.
| static GEOMEXPORT void XYZtoRGB | ( | const float | xyz[3], |
| float | rgb[3] | ||
| ) | [static] |
- Remarks:
- This method converts from XYZ space to RGB space.
- Parameters:
- const float xyz[3]
The input values to convert.
float rgb[3]
The output values are stored here.
| static GEOMEXPORT void RGBtoXYZ | ( | const float | rgb[3], |
| float | xyz[3] | ||
| ) | [static] |
- Remarks:
- This method converts from RGB space to XYZ space.
- Parameters:
- const float rgb[3]
The input values to convert.
float xyz[3]
The output values are stored here.
Member Data Documentation
| DWORD32 value |
Storage for the pixel value.
