ImageGear for C and C++ on Windows v19.10 - Updated
MED_IP_contrast_auto_double
API Reference Guide > MD Component API Reference > MD Component Functions Reference > Image Processing Functions > MED_IP_contrast_auto_double

This function converts a 16-bit grayscale image to an 8-bit grayscale image using the same function as MED_display_contrast_auto_double() except that this function permanently alters the pixel values.

Declaration:

 
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AT_ERRCOUNT ACCUAPI MED_IP_contrast_auto_double(
        const HIGEAR hIGear, 
        const LPAT_RECT lpRect, 
        const DOUBLE rescale_slope, 
        const DOUBLE rescale_intercept, 
        const DOUBLE gamma,
        const LONG lReserved_option, 
        LPDOUBLE lpWindow_center, 
        LPDOUBLE 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 const DOUBLE Non-linear method to adjust the contrast of DICOM image. In this method, the amount a pixel's intensity changes depends on its original intensity. Usual range is 0.75 to 3.0.
lReserved_option const LONG Reserved for future use; please set to 0 for now.
lpWindow_center LPDOUBLE A far pointer that returns a LONG for the Window Center; set to NULL if you don't need this information.
lpWindow_width LPDOUBLE A far pointer that returns a LONG for the Window Width; set to NULL if you don't need this information.

Supported Raster Image Formats:

Grayscale – 9…16 bpp.

Return Value:

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

See Also

MED_display_contrast_auto_double()

MED_IP_reduce_depth_with_downshift()