VImage VImageManager::scaleImage( VImage src, VImage dest, double factor )
{
int nPixel = VImageSize( src ) / VPixelSize( src );
if ( dest == NULL ) {
dest = VCreateImage(
VImageNBands( src ),
VImageNRows( src ),
VImageNColumns( src ),
VUByteRepn );
}
VUByte *destPtr = ( VUByte * ) VImageData( dest );
VShort *srcPtr = ( VShort * ) VImageData( src );
srcPtr = ( VShort * ) VImageData( src );
for ( int i = 0; i < nPixel; i++ ) {
if ( *srcPtr <= m_xmin )
*destPtr = 0;
else if ( *srcPtr >= m_xmax )
*destPtr = 255;
else {
int val = *srcPtr - m_xmin;
*destPtr = ( VUByte ) ( val * factor );
}
srcPtr++;
destPtr++;
}
return dest;
}
static VPointer VImageDecodeMethod (VStringConst name, VBundle b)
{
VImage image;
VLong nbands, nrows, ncolumns, pixel_repn;
VLong nframes, nviewpoints, ncolors, ncomponents;
VAttrList list;
size_t length;
#define Extract(name, dict, locn, required) \
VExtractAttr (b->list, name, dict, VLongRepn, & locn, required)
/* Extract the number of bands, rows, columns, pixel repn, etc.: */
nbands = nframes = nviewpoints = ncolors = ncomponents = 1; /* defaults */
if (! Extract (VNBandsAttr, NULL, nbands, FALSE) ||
! Extract (VNRowsAttr, NULL, nrows, TRUE) ||
! Extract (VNColumnsAttr, NULL, ncolumns, TRUE) ||
! Extract (VRepnAttr, VNumericRepnDict, pixel_repn, TRUE) ||
! Extract (VNFramesAttr, NULL, nframes, FALSE) ||
! Extract (VNViewpointsAttr, NULL, nviewpoints, FALSE) ||
! Extract (VNColorsAttr, NULL, ncolors, FALSE) ||
! Extract (VNComponentsAttr, NULL, ncomponents, FALSE))
return NULL;
/* Ensure that nbands == nframes * nviewpoints * ncolors * ncomponents.
For backwards compatibility, set ncomponents to nbands if nbands != 1
but nframes == nviewpoints == ncolors == ncomponents == 1. */
if (nbands != nframes * nviewpoints * ncolors * ncomponents) {
if (nbands != 1 && nframes == 1 && nviewpoints == 1 &&
ncolors == 1 && ncomponents == 1)
ncomponents = nbands;
else {
VWarning ("VImageDecodeMethod: %s image has inconsistent nbands",
name);
return NULL;
}
}
/* Create an image with the specified properties: */
if (! (image = VCreateImage ((int) nbands, (int) nrows, (int) ncolumns,
(VRepnKind) pixel_repn)))
return NULL;
VImageNFrames (image) = nframes;
VImageNViewpoints (image) = nviewpoints;
VImageNColors (image) = ncolors;
VImageNComponents (image) = ncomponents;
/* Give it whatever attributes remain: */
list = VImageAttrList (image);
VImageAttrList (image) = b->list;
b->list = list;
/* Check that the expected amount of binary data was read: */
length = VImageNPixels (image);
if (VPixelRepn (image) == VBitRepn)
length = (length + 7) / 8;
else length *= VPixelPrecision (image) / 8;
if (length != b->length) {
VWarning ("VImageDecodeMethod: %s image has wrong data length", name);
Fail: VDestroyImage (image);
return NULL;
}
/* Unpack the binary pixel data: */
length = VImageSize (image);
if (! VUnpackData (VPixelRepn (image), VImageNPixels (image),
b->data, VMsbFirst, & length, & VImageData (image),
NULL))
goto Fail;
return image;
#undef Extract
}
