LBitmap::GammaCorrect
#include "ltwrappr.h"
virtual L_INT LBitmap::GammaCorrect(uGamma)
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L_UINT uGamma; |
/* unsigned integer that represents the gamma value */ |
Adjusts the intensity of colors in the class object's bitmap by changing the gamma constant that is used to map the intensity values.
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Parameter |
Description |
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uGamma |
Unsigned integer that represents the gamma value. It can be any number greater than 0. |
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Because this is an unsigned integer, it is 100 times the actual gamma value. For example, use 235 to set a gamma value of 2.35. |
Returns
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SUCCESS |
The function was successful. |
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< 1 |
An error occurred. Refer to Return Codes. |
Comments
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.
When applying contrast, gamma, and intensity changes to a bitmap, LEAD applies the changes in the following order:
Contrast
Intensity
Gamma
Required DLLs and Libraries
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LTDIS 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("V:\\images\\babe.cmp"), 0,ORDER_BGR);
LeadBitmap.GammaCorrect(235);