Intel® Integrated Performance Primitives (Intel® IPP) Developer Guide and Reference
A newer version of this document is available. Customers should click here to go to the newest version.
ImageRamp
Creates a test image that has an intensity ramp.
Syntax
IppStatus ippiImageRamp_<mod>(Ipp<datatype>* pDst, int dstStep, IppiSize roiSize, float offset, float slope, IppiAxis axis);
Supported values for mod:
| 8u_C1R | 16u_C1R | 16s_C1R | 32f_C1R | 
| 8u_C3R | 16u_C3R | 16s_C3R | 32f_C3R | 
| 8u_C4R | 16u_C4R | 16s_C4R | 32f_C4R | 
| 8u_AC4R | 16u_AC4R | 16s_AC4R | 32f_AC4R | 
Include Files
ippi.h
Domain Dependencies
Headers: ippcore.h, ippvm.h, ipps.h
Libraries: ippcore.lib, ippvm.lib, ipps.lib
Parameters
| pDst | Pointer to the destination image ROI. | ||||||
| dstStep | Distance in bytes between starts of consecutive lines in the destination image. | ||||||
| roiSize | Size of the destination image ROI in pixels. | ||||||
| offset | Offset value. | ||||||
| slope | Slope coefficient. | ||||||
| axis | Specifies the direction of the image intensity ramp; can be one of the following: 
 | 
Description
This function operates with ROI (see Regions of Interest in Intel IPP).
The function creates a one- or three-channel image that can be used as a test image to examine the effect of applying different image processing functions.
The destination image pixel values are computed according to one of the following formulas:
dst(x,y) = offset + slope * x, if axis = ippAxsHorizontal,
dst(x,y) = offset + slope * y, if axis = ippAxsVertical,
dst(x,y) = offset + slope * x * y, if axis = ippAxsBoth,
where x, y are pixel coordinates varying in the range
0 ≤ x ≤roiSize.width-1, 0 ≤ y ≤roiSize.height-1;
Note that linear transform coefficients offset and slope have floating-point values for all function flavors. The computed pixel values that exceed the image data range are saturated to the respective data-range limits.
Return Values
| ippStsNoErr | Indicates no error. Any other value indicates an error or a warning. | 
| ippStsNullPtrErr | Indicates an error condition if the pDst pointer is NULL. | 
| ippStsSizeErr | Indicates an error condition if roiSize has a field with a zero or negative value, or if dstStep is less than or equal to zero. | 
Example
The code example below illustrates how to use the ippiImageRamp function.
IppStatus ramp( void ){
   Ipp8u dst[8*4];
   IppiSize roiSize = { 8, 4 };
   return ippiImageRamp_8u_C1R( dst, 8, roiSize, 0.0f, 256.0f/7,  ippAxsHorizontal);
} The destination image contains the following data: 
   00 25 49 6E 92 B7 DB FF 00 25 49 6E 92 B7 DB FF 00 25 49 6E 92 B7 DB FF 00 25 49 6E 92 B7 DB FF