Creates Jaehne test image.
Syntax
IppStatus ippiImageJaehne_<mod>(Ipp<datatype>* pDst, int dstStep, IppiSize roiSize);
Supported values for mod:
| 8u_C1R | 8s_C1R | 16u_C1R | 16s_C1R | 32s_C1R | 32f_C1R |
| 8u_C3R | 8s_C3R | 16u_C3R | 16s_C3R | 32s_C3R | 32f_C3R |
| 8u_C4R | 8s_C4R | 16u_C4R | 16s_C4R | 32s_C4R | 32f_C4R |
| 8u_AC4R | 8s_AC4R | 16u_AC4R | 16s_AC4R | 32s_AC4R | 32f_AC4R |
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. |
Description
The function ippiImageJaehne is declared in the ippi.h file. It operates with ROI (see Regions of Interest in Intel IPP).
This function creates a specific one- or three-channel test image that has been first introduced to digital image processing by B.Jaehne (see [Jae95]).
The destination image pixel values are computed according to the following formula:
Dst(x,y) = A*sin(0.5*IPP_PI* (x22 + y22) / roiSize.height),
where x, y are pixel coordinates varying in the range
0 ≤ x ≤ roiSize.width-1, 0 ≤ y ≤ roiSize.height-1;
IPP_PI is the library constant that stands for π value.
x2 = (x-roiSize.width+1)/2.0,
y2 = (y-roiSize.height+1)/2.0,
A is the constant value that depends upon the image type being created.
For the 32f floating point data, the pixel values in the created image can vary in the range between 0 (inclusive) and 1 (exclusive).
Figure Example of a Generated Jaehne's Test Image illustrates an example of a test image generated by the ippiImageJaehne function.
These test images can be effectively used when you need to visualize and interpret the results of applying filtering functions, similarly to what is proposed in [Jae95].
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. |