MED_display_contrast

This function automatically fills the 16x8 LUT of a 16-bit image loaded into ImageGear in order to optimize its displaying.

Declaration:

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AT_ERRCOUNT ACCUAPI MED_display_contrast_auto( const HIGEAR hIGear, const LPAT_RECT lpRect, const DOUBLE rescale_slope, const DOUBLE rescale_intercept, const DOUBLE gamma, const LONG lReserved_option, LPLONG lpWindow_center, LPLONG lpWindow_width );

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AT_ERRCOUNT ACCUAPI MED_display_contrast_auto(
        const HIGEAR hIGear, 
        const LPAT_RECT lpRect, 
        const DOUBLE rescale_slope, 
        const DOUBLE rescale_intercept,
        const DOUBLE gamma,
        const LONG lReserved_option, 
        LPLONG lpWindow_center, 
        LPLONG lpWindow_width
);

Arguments:

Name	Type	Description
hIGear	const HIGEAR	The HIGEAR handle to the image to convert.
lpRect	const AT_RECT	Use this AT_RECT structure to specify the rectangular portion of the image for which to optimize the contrast on; set to NULL for the whole image. Please see the ImageGear User's Manual if you are unfamiliar with this structure.
rescale_slope	const DOUBLE	Set to the value of the Data Element, Rescale Slope (0028,1053). You can use MED_DCM_DS_Rescale_get() to obtain this value. If this Data Element is not present in the Data Set, please set this value to 1.0.
rescale_intercept	const DOUBLE	Set to the value of the Data Element, Rescale Intercept (0028,1054). You can use MED_DCM_DS_Rescale_get() to obtain this value. If this Data Element is not present in the Data Set, please set this value to 0.0.
gamma	DOUBLE	Gamma correction for 16x8 Lookup Table. Set to 1.0 to turn the correction off.
lReserved_option	const LONG	Reserved for future use; please set to 0 for now.
lpWindow_center	LPLONG	A far pointer that returns a LONG for the Window Center; set to NULL if you don't need this information.
lpWindow_width	LPLONG	A far pointer that returns a LONG for the Window Width; set to NULL if you don't need this information.

Return Value:

Returns the number of ImageGear errors that occurred during the function call.

Supported Raster Image Formats:

Grayscale – 8…32 bpp.

Example:

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HIGEAR hIGear; DOUBLE fRescaleSlope = 1.0; DOUBLE fRescaleIntercept = 1.0; DOUBLE fGama = 1.0; LONG WindowWidth; LONG WindowCenter; MED_display_contrast_auto(hIGear, NULL, fRescaleSlope, fRescaleIntercept, fGamma, 0, &WindowCenter, &WindowWidth);

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HIGEAR hIGear;
DOUBLE          fRescaleSlope = 1.0;
DOUBLE          fRescaleIntercept = 1.0;
DOUBLE          fGama = 1.0;
LONG            WindowWidth;
LONG            WindowCenter;
MED_display_contrast_auto(hIGear, NULL, fRescaleSlope, 
                        fRescaleIntercept, fGamma, 0, &WindowCenter,  
                                                    &WindowWidth);

Remarks:

The rectangular portion of the image that you specify (or the whole image) is scanned and the maximum and minimum pixel values are determined; the Window Center and Width are calculated from these.

If the Rescale Slope and Intercept of the image are known, you should provide them. If they are not known, pass in a 1.0 and 0.0, respectively.

The Window Center and Width that this function computes are passed back to you in lpWindow_center and lpWindow_width, unless you set these arguments to NULL.

This function does not cause the image to be displayed or repainted. It only fills the 16x8 LUT. To display the results of this function, use IG_dspl_image_draw().