Intel® Integrated Performance Primitives

Need help with ippiwinHamming_32f_C1IR

Hi,

I'm trying to use Hamming window functions in my program before applying FFT on images. There are two image processing functions for Hamming: ippiWinHamming_32f_C1IR and ippiWinHammingSep_32f_C1IR. I do not know which one should I use.

Can someone tell me whats the difference between those two hamming ippi functions? What effect will be there if I choose ippiWinHamming_32f_C1IR over ippiWinHammingSep_32f_C1IR  on FFT?

ippiLUTPalette inline

Couldn't find inline variants of the ippiLUTPalette functions. So, I tried passing the same image parameters for source and destination in ippiLUTPalette_16u_AC4R. Well, it did the job, didn't crash.

Any comments ?

I now have the same issue with ippiRGBToHSV et all, no inline variants.

Regards,

Adriaan van Os

 

stride misalignment on purpose

Hi,

I remember reading a whitepaper I can't now find that argued that you shouldn't over-align, specially for Pentium 4. Image stride should be a multiple of 64 but not 128, to prevent columns fighting for the same cache lines. Otherwise most of the cache is useless. For example, if a 32KB cache is 4-way associative and each line 64 bytes long, only 4x64 = 256 bytes are used.

iw doesn't take this precaution. Maybe it should? Any pointers to read more on this and why Pentium 4 had it worse than other CPUs?

Bruno

IPP 2018 Update 1 - ippInit issue

Hello,

Recently we have updated IPP library to 2018 update 1 and we encounter a series of application crush. We have noticed that the reason for failure is the ippInit function which returns non zero status. We have encountered this error for processor Intel I7-7700k. The ippInit function returns code 49 (ippStsFeatureNotSupported) for this processor even though the value is not specified in the documentation. Apart from the erroneous status the AVX and AVX2 features are disabled. Our investigation showed that the ippInit function is written as 

Difference in the output of Nearest Neighbour resize using IPP 7.0 resize/ippiResize_16u_C1R and API and IPP 2017-ResizeNearest

HI All,

I am trying resize my images using IPPI_INTER_NN. When I have used IPP 7.0 Resize-ippiResize_16u_C1R to resize image my output is very much different from the same generated through  IPP 2017/9.-0 -ResizeNearest.

Plz suggests what is the cause of this.

Regards,

Sumit Jha

Difference between output of "ippsPowx_32f_A24" in IPP 7.0 and IPP 2017-(9.0)

Hi All,

I am using ippsPowx_32f_A24 is one of my old application which uses IPP 7.0. But now I am moving this code into IPP 2017. I am seeing difference in the outputs between these two. I want to raise the power of X(int) on float number-B i.e B^(X).

Please suggest if there any change in the API usage.

 

Regards,

Sumit jha

 

Pan/Zoom image using ResizeLanczos

I am having trouble with ref function/ functionality - code below. When I increase dZoom beyond some value it crashes. It also misaligns the rows of the output image (I uploaded an image showing this). Input/Output is grayscale (8u). I likely have an incorrect understanding of sizeSrc, sizeDst and zoomImgSize. Can someone please check what is going on?

Thank you!

ippsFFTwd_CToC_64fc_I only updates on first call

Hi,

I am using FFT calculation in my app. when calling ippsFFTwd_CToC_64fc_I the buffer values updates only on the first iteration call.

From second iteration, the buffer values are always the same as the values I've received on the first iteration.

what could be the cause of that?

thanks,

Gil

Subscribe to Intel® Integrated Performance Primitives