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bibi88
Beginner
35 Views

OpenCV to IPP

Hello,

I've some problem, trying to convert the linear structure of an IPL (OpenCV) image into an IPP image structure.
When I display the IPP matrix of the picture, it appears that it's not the expected one.
Here is my code:

typedef struct IppImage_8u IppImage_8u;
struct IppImage_8u{
Ipp8u* data[4]; // 4 layers (RGB for example+gamma)
int width[4];
int height[4];
int stepWidth[4];
};

IplImage* pcv_Img contains an image.
IppImage_8u* pipp_Img is allocated (sizeof(IppImage_8u))
pipp_Img->data[0] = NULL;
pipp_Img->data[1] = NULL;
pipp_Img->data[2] = NULL;
pipp_Img->data[0] = ippiMalloc_8u_C1(pcv_Img->width, pcv_Img->height, &(pipp_Img->stepWidth[0]));
pipp_Img->data[1] = ippiMalloc_8u_C1(pcv_Img->width, pcv_Img->height, &(pipp_Img->stepWidth[1]));
pipp_Img->data[2] = ippiMalloc_8u_C1(pcv_Img->width, pcv_Img->height, &(pipp_Img->stepWidth[2]));
pipp_Img->data[0] = (Ipp8u *) &pcv_Img->imageData[0];
pipp_Img->data[1] = (Ipp8u *) &pcv_Img->imageData[pcv_Img->width*pcv_Img->height];
pipp_Img->data[2] = (Ipp8u *) &pcv_Img->imageData[2*pcv_Img->width*pcv_Img->height];
pipp_Img->width[0] = pcv_Img->width;
pipp_Img->width[1] = pcv_Img->width;
pipp_Img->width[2] = pcv_Img->width;
pipp_Img->height[0] = pcv_Img->height;
pipp_Img->height[1] = pcv_Img->height;
pipp_Img->height[2] = pcv_Img->height;


Here is the displaying method that I use:

int i,j,k;
for (k=0;k<3;k++)
{
for (i=0;iheight;i++)
{
for (j=0;jwidth;j++)
{
printf("%d ",pipp_Img->data[i*pipp_Img->widthStep+j]);
}
printf("\\n");
}
printf("\\n \\n \\n");
}

The displayed number doesn't correspond to what, for example, Matlab says. Could you please explain me why?

Thanks in advance for your help!
0 Kudos
4 Replies
Vladimir_Dudnik
Employee
35 Views

Hello,

unfortunately I did not get the idea you show with code snippet. Why do you overwrite pipp_Img->data pointers?

pipp_Img->data[0] = ippiMalloc_8u_C1(pcv_Img->width, pcv_Img->height, &(pipp_Img->stepWidth[0]));
pipp_Img->data[1] = ippiMalloc_8u_C1(pcv_Img->width, pcv_Img->height, &(pipp_Img->stepWidth[1]));
pipp_Img->data[2] = ippiMalloc_8u_C1(pcv_Img->width, pcv_Img->height, &(pipp_Img->stepWidth[2]));

// the assigments below will overwrite pipp_Img->data pointers, resulting in loose of just allocated memory
pipp_Img->data[0] = (Ipp8u *) &pcv_Img->imageData[0];
pipp_Img->data[1] = (Ipp8u *) &pcv_Img->imageData[pcv_Img->width*pcv_Img->height];
pipp_Img->data[2] = (Ipp8u *) &pcv_Img->imageData[2*pcv_Img->width*pcv_Img->height];

If you try to represent IplImage datawith your IppImage_8u data structure you also need to ensure you use IplImage step (aka pitch) to navigate correctlythrough IplImage pixels.

Vladimir
bibi88
Beginner
35 Views

Hello,

Sorry for the misunderstanding! My problem is quite easy in fact. I've a 3 component picture in a format char* old_version_data, with height "old_version_height", width "old_version_width" and a pitch "old_version_pitch".
I would like to get this picture in an ippi format, so I've defined a Ipp8u* ipp_data[3], IppSize ipp_size and int ipp_pitch.
How can I do the translation from "old_version" to ipp?

Thanks in advance!
Ying_H_Intel
Employee
35 Views

Hello bibi88,

No sure if i understand correct,

but if youare using thestructIplImage* pcv_Img in OpenCV( i.e OpenCV 2.1.0), then the two struct of IPL image and IPP image is almost aligned witheach other, you don't need to any change.

For example
// 3 channel image
IplImage* pSrcImg = cvLoadImage( "testimg.bmp", 1 );
int SRC_WIDTH= pSrcImg->width;
int SRC_HEIGHT=pSrcImg->height;
CvSize cvsrcSize={ SRC_WIDTH,SRC_HEIGHT};
IppiSize t_size={SRC_WIDTH, SRC_HEIGHT};

when call ipp function (ipp image)
the width is same, height is same, step is same. Just please notes theimageData pointer.

// copy the OpenCV IPL image to IPP image
Ipp8u *ipp_template = ippiMalloc_8u_C3( SRC_WIDTH, SRC_HEIGHT, &stepByte );
ippiCopy_8u_C3R((Ipp8u*)pSrcImg->imageData, (Ipp8u) pSrcImg->widthStep, ipp_template, stepByte, t_size);
more dicussion are in Intel Ipp - Open Source Computer Vision Library (OpenCV) FAQ


So reviewyour code, 3 commponent picture or4 layers (RGB for example+gamma).
the keyproblem is the storage format.
is it
RGBRGBRGBRGB...
or
RRRRRRR
GGGGGGG
BBBBBBB ?

If it is former, then the stucture is alignment naturally as above sample. The convertion is not needed.

If it is latter,
first the memory allocation is not needed
pipp_Img->data[0] = ippiMalloc_8u_C1(pcv_Img->width, pcv_Img->height, &(pipp_Img->stepWidth[0]));
pipp_Img->data[1] = ippiMalloc_8u_C1(pcv_Img->width, pcv_Img->height, &(pipp_Img->stepWidth[1]));
pipp_Img->data[2] = ippiMalloc_8u_C1(pcv_Img->width, pcv_Img->height, &(pipp_Img->stepWidth[2]));

It is ok to use the memory from pcv_Image.
But second question, are you sure the R frame and G frame and B frame are stored in IPL like the below? (could you show how*version_version_datadefined based onpcv_Img?)
pipp_Img->data[0] = (Ipp8u *) &pcv_Img->imageData[0];
pipp_Img->data[1] = (Ipp8u *) &pcv_Img->imageData[pcv_Img->width*pcv_Img->height];
pipp_Img->data[2] = (Ipp8u *) &pcv_Img->imageData[2*pcv_Img->width*pcv_Img->height];

According to your code
int i,j,k;
for (k=0;k<3;k++)
{
for (i=0;iheight;i++)
{
for (j=0;jwidth;j++)
{
printf("%d ",pipp_Img->data[i*pipp_Img->widthStep+j]);
}
printf("\n");
}
printf("\n \n \n");
}

It seems
at least should be

pipp_Img->data[0] = (Ipp8u *) &pcv_Img->imageData[0];
pipp_Img->data[1] = (Ipp8u *) &pcv_Img->imageData[pcv_Img->widthStep*pcv_Img->height];
pipp_Img->data[2] = (Ipp8u *) &pcv_Img->imageData[2*pcv_Img->widthStep*pcv_Img->height];

Please notes the width is not widthStep
(awhole rowin bytes, may be 4 bytes align of 32 bytes align).

Regards,
Ying
bibi88
Beginner
35 Views

Thank you very much, IplImage was following the interleaved format (RGB RGB RGB and not a planar RRR GGG BBB), that's why I had so many problems! Sorry for my dummy question!