LBitmapRgn::SetRgnColorHSVRange

#include "ltwrappr.h"

virtual L_INT LBitmapRgn::SetRgnColorHSVRange(hsvLower, hsvUpper)

HSVREF hsvLower;	/* minimum HSV color value */
HSVREF hsvUpper;	/* maximum HSV color value */

Creates or updates the bitmap region by adding a region that consists of all the pixels that fall in the range hsvLower ... hsvUpper, inclusively.

Parameter	Description
hsvLower	Structure that contains the minimum (inclusive) H, S, and V values. A pixel must have H, S, and V all greater than or equal to hsvLower and less than or equal to hsvUpper to be included in the region.
hsvUpper	Structure that contains the maximum (inclusive) H, S, and V values. A pixel must have H ,S, and V all greater than or equal to hsvLower and less than or equal to hsvUpper to be included in the region.

Returns

SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

This function uses the HSV color model to set a region based on a color range.

It is useful for identifying all shades of a certain color. For example, LBitmapRgn::SetRgnColorHSVRange could be used to set a region of all green colors including:

RGB(0,1,0)
RGB(0,2,0)	RGB(1,2,1)
RGB(0,3,0)	RGB(1,3,1)	RGB(2,3,2)
...	...	...
RGB(0,255,0)	RGB(1,255,1)	RGB(2,255,2)

The diagram below shows how S and V affect the color green (H = 85)

$image\HueTable.gif$

To be added to the region a color must fall in the range hsvLower..hsvUpper. If you want to set a region for all red (and colors near red), you could specify hsvLower and hsvUpper as follows:

hsvLower(250,1,1)
hsvUpper(5,255,255)

Note that hue for hsvLower is 250 and hue for hsvUpper is 5. For a hue to fall in this range, it must be either 250, 251, 252, 253, 254, 255, 1, 2, 3, 4, or 5. Also, note that the hue values wrap from 255 back around to 1.

To update an existing region, specify how the new region is to be combined with the existing one. For descriptions of the possibilities, refer to Creating a Bitmap Region.

This function does not support signed data images. It returns the error code ERROR_SIGNED_DATA_NOT_SUPPORTED if a signed data image is passed to this function.

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

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

Functions:	LBitmap::RemapHue, LBitmapRgn::SetRgnColorRGBRange, LBitmapRgn::SetRgnEllipse, LBitmapRgn::SetRgnPolygon, LBitmapRgn::SetRgnRect, LBitmapRgn::SetRgnRoundRect
Topics:	Raster Image Functions: Creating and Using a Region
	Working with the Existing Bitmap Region
	Saving a Region

Example

//This example sets a region corresponding to all pure green (Hue = 85)
//and colors near green (+/- 10)
//where Saturation is at least 40 and Value is at least 40
L_INT SetHSVRgnExample(LBitmapRgn& rgn)
{
   HSVREF hsvLo, hsvHi;
   L_INT nRet;

   hsvLo.uH = 75;
   hsvLo.uS = 40;
   hsvLo.uV = 40;

   hsvHi.uH = 95;
   hsvHi.uS = 255;
   hsvHi.uV = 255;

   nRet = rgn.SetRgnColorHSVRange(hsvLo,hsvHi);
   return nRet;
}