LBitmap::GammaCorrectExt
#include "ltwrappr.h"
L_INT LBitmap::GammaCorrectExt(uGamma, uFlag)
L_UINT uGamma; |
/* gamma value */ |
L_UINT uFlag; |
/* flag */ |
Adjusts the intensity of colors in a bitmap by changing the gamma constant that is used to map the intensity values. Either of two different color spaces can be specified.
Parameter |
Description |
|
uGamma |
Any value greater than 0 that represents the gamma value. This value is divided internally by 100. |
|
uFlag |
Flag that indicates which color space to use. Possible values are: |
|
|
Value |
Meaning |
|
RGB_SPACE |
[0x0001] Adjust the intensity of the pixel colors across the RGB color space. |
|
YUV_SPACE |
[0x0002] Adjust the intensity of the pixel colors across the YUV color space. |
Returns
SUCCESS |
The function was successful. |
< 1 |
An error occurred. Refer to Return Codes. |
Comments
This function is like the LBitmap::GammaCorrect function, but has been extended to allow the specification of the color space to be used.
Intensity values ideally follow a logarithmic progression, because the eye perceives changes in intensity as being equal when the ratio of change is equal. For example, we would see a change from 0.1 to 0.2 as being equal to a change from 0.2 to 0.4.
Gamma is a standard constant that is used to calculate the progression. For most CRTs the gamma constant is in the range of 2.2 to 2.5.
To update a status bar or detect a user interrupt during execution of this function, refer to LBase::EnableStatusCallback.
This function supports 12 and 16-bit grayscale and 48 and 64-bit color images. Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available only in the Document/Medical toolkits.
Required DLLs and Libraries
LTIMG For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application. |
See Also
Example
LBitmap LeadBitmap;
LeadBitmap.Load(TEXT("C:\\IMAGE4.CMP"), 0,ORDER_BGR);
LeadBitmap.GammaCorrectExt (250, YUV_SPACE);