Resize function ippiResizeSqrPixel() crashed for small image

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October 13, 2009 7:00 AM PDT


The Intel® IPP Resize function ippiResizeSqrPixel crashed when the image size is less than 6 and use interpolation method LANCZOS or CUBIC. It is an issue we recently identified in IPP v 6.0

Here is sample code.  main_ippiResize.cpp

It calls ippiResizeSqrPixel_8u_C3R() to stretch 3x4 source image to 17x23 image
/* set/calculate of the x, y dimensions Factors,Shift Value,Interpolation value
	please note, xFactor is double type float point number. 
	*/
	double xFactor = (double)dstWidth / srcWidth;
	double yFactor = (double)dstHeight / srcHeight;
	double xShift = 0.0;
	double yShift = 0.0;
	/* interploation options are:
	   IPPI_INTER_NN||IPPI_INTER_LINEAR|| IPPI_INTER_CUBIC
	   IPPI_INTER_CUBIC2P_BSPLINE||IPPI_INTER_CUBIC2P_CATMULLROM||PPI_INTER_CUBIC2P_B05C03
	   IPPI_INTER_SUPER||IPPI_INTER_LANCZOS */
	int interpolation = IPPI_INTER_LANCZOS;

    /* calculation of work buffer size */
	Ipp8u * pBuffer;
	int bufSize = 0;
	ippiResizeGetBufSize(srcRoi, dstRoi, nChannel, interpolation, &bufSize );
    pBuffer= ippsMalloc_8u(bufSize );

    /* Resize Image */
	status=ippiResizeSqrPixel_8u_C3R(pSrc, srcSize, srcStep, srcRoi, pDst, dstStep,
	 dstRoi, xFactor, yFactor, xShift, yShift, interpolation, pBuffer);
	printf("%d : %s\n", status, ippGetStatusString(status));

The fix have been available in Intel® IPP 6.1 update 1 (6.1.1.035).

A quick workaround is to change interpolation type for very small source images.  Please add the below code after line 9:

if (srcWidth < 6 || srcHeight< 6) {
        if (interpolation == IPPI_INTER_LANCZOS)
            interpolation = IPPI_INTER_CUBIC;
        if (srcWidth < 4 || srcHeight < 4) {
            if ((interpolation == IPPI_INTER_CUBIC) ||
                (interpolation == IPPI_INTER_CUBIC2P_BSPLINE) ||
                (interpolation == IPPI_INTER_CUBIC2P_CATMULLROM) ||
                (interpolation == IPPI_INTER_CUBIC2P_B05C03))
                interpolation = IPPI_INTER_LINEAR;
        }
}


Other common errors:
1. Wrong stepBytes value
For example,
the srcStep != channel*srcWidth in most of cases.
It may be    = ((nChannel*srcWidth+3)>>2)<<2 if a bmp image with 4 bytes-aligned,
or               = a multiple of 32 when use ippiMalloc() as each row is 32 bytes-aligned

2. Wrong factor value
xFactor and yFactor are double type. For example, for accurate stretch src image to dst image, it should be double xFactor = (double)dstWidth / srcWidth;not double xFactor = dstWidth / srcWidth;
The four double parameters allow full coordinates transformation
|dX|     |xFactor  0 |    |sX|      |xShift|
|    | =  |               | * |    | +  |        |
|dY|      | 0  yFactor|   |sY |     |yShift|

3.  About srcROI and dstROI
Please see the discussion and illustrated figure on forum


Do you need more help?
Article Attachments
main_ippiResize.cpp


This article applies to: Intel® Integrated Performance Primitives Knowledge Base