/*
-----------------------------------------------------------------------
Copyright: 2010-2015, iMinds-Vision Lab, University of Antwerp
2014-2015, CWI, Amsterdam
Contact: astra@uantwerpen.be
Website: http://sf.net/projects/astra-toolbox
This file is part of the ASTRA Toolbox.
The ASTRA Toolbox is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
The ASTRA Toolbox is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with the ASTRA Toolbox. If not, see .
-----------------------------------------------------------------------
$Id$
*/
#include
#include
#include
#include
#include
#include "util3d.h"
#ifdef STANDALONE
#include "cone_fp.h"
#include "testutil.h"
#endif
#include "dims3d.h"
#include "arith3d.h"
#include "../2d/fft.h"
typedef texture texture3D;
static texture3D gT_coneProjTexture;
namespace astraCUDA3d {
static const unsigned int g_volBlockZ = 16;
static const unsigned int g_anglesPerBlock = 64;
static const unsigned int g_volBlockX = 32;
static const unsigned int g_volBlockY = 16;
static const unsigned int g_anglesPerWeightBlock = 16;
static const unsigned int g_detBlockU = 32;
static const unsigned int g_detBlockV = 32;
static const unsigned g_MaxAngles = 2048;
__constant__ float gC_angle_sin[g_MaxAngles];
__constant__ float gC_angle_cos[g_MaxAngles];
__constant__ float gC_angle[g_MaxAngles];
// per-detector u/v shifts?
static bool bindProjDataTexture(const cudaArray* array)
{
cudaChannelFormatDesc channelDesc = cudaCreateChannelDesc();
gT_coneProjTexture.addressMode[0] = cudaAddressModeBorder;
gT_coneProjTexture.addressMode[1] = cudaAddressModeBorder;
gT_coneProjTexture.addressMode[2] = cudaAddressModeBorder;
gT_coneProjTexture.filterMode = cudaFilterModeLinear;
gT_coneProjTexture.normalized = false;
cudaBindTextureToArray(gT_coneProjTexture, array, channelDesc);
// TODO: error value?
return true;
}
__global__ void devBP_FDK(void* D_volData, unsigned int volPitch, int startAngle, float fSrcOrigin, float fDetOrigin, float fSrcZ, float fDetZ, float fInvDetUSize, float fInvDetVSize, const SDimensions3D dims)
{
float* volData = (float*)D_volData;
int endAngle = startAngle + g_anglesPerBlock;
if (endAngle > dims.iProjAngles)
endAngle = dims.iProjAngles;
// threadIdx: x = rel x
// y = rel y
// blockIdx: x = x + y
// y = z
// TO TRY: precompute part of detector intersection formulas in shared mem?
// TO TRY: inner loop over z, gather ray values in shared mem
const int X = blockIdx.x % ((dims.iVolX+g_volBlockX-1)/g_volBlockX) * g_volBlockX + threadIdx.x;
const int Y = blockIdx.x / ((dims.iVolX+g_volBlockX-1)/g_volBlockX) * g_volBlockY + threadIdx.y;
if (X > dims.iVolX)
return;
if (Y > dims.iVolY)
return;
const int startZ = blockIdx.y * g_volBlockZ;
int endZ = startZ + g_volBlockZ;
if (endZ > dims.iVolZ)
endZ = dims.iVolZ;
float fX = X - 0.5f*dims.iVolX + 0.5f;
float fY = Y - 0.5f*dims.iVolY + 0.5f;
float fZ = startZ - 0.5f*dims.iVolZ + 0.5f - fSrcZ;
const float fU_base = 0.5f*dims.iProjU - 0.5f + 0.5f;
const float fV_base = 0.5f*dims.iProjV - 0.5f + 0.5f + (fDetZ-fSrcZ);
// Note re. fZ/rV_base: the computations below are all relative to the
// optical axis, so we do the Z-adjustments beforehand.
for (int Z = startZ; Z < endZ; ++Z, fZ += 1.0f)
{
float fVal = 0.0f;
float fAngle = startAngle + 0.5f;
for (int angle = startAngle; angle < endAngle; ++angle, fAngle += 1.0f)
{
const float cos_theta = gC_angle_cos[angle];
const float sin_theta = gC_angle_sin[angle];
const float fR = fSrcOrigin;
const float fD = fR - fX * sin_theta + fY * cos_theta;
float fWeight = fR / fD;
fWeight *= fWeight;
const float fScaleFactor = (fR + fDetOrigin) / fD;
const float fU = fU_base + (fX*cos_theta+fY*sin_theta) * fScaleFactor * fInvDetUSize;
const float fV = fV_base + fZ * fScaleFactor * fInvDetVSize;
fVal += tex3D(gT_coneProjTexture, fU, fAngle, fV);
}
volData[(Z*dims.iVolY+Y)*volPitch+X] += fVal;
// projData[(angle*dims.iProjV+detectorV)*projPitch+detectorU] = 10.0f;
// if (threadIdx.x == 0 && threadIdx.y == 0) { printf("%d,%d,%d [%d / %d] -> %f\n", angle, detectorU, detectorV, (angle*dims.iProjV+detectorV)*projPitch+detectorU, projPitch, projData[(angle*dims.iProjV+detectorV)*projPitch+detectorU]); }
}
}
bool FDK_BP(cudaPitchedPtr D_volumeData,
cudaPitchedPtr D_projData,
float fSrcOrigin, float fDetOrigin,
float fSrcZ, float fDetZ, float fDetUSize, float fDetVSize,
const SDimensions3D& dims, const float* angles)
{
// transfer projections to array
cudaArray* cuArray = allocateProjectionArray(dims);
transferProjectionsToArray(D_projData, cuArray, dims);
bindProjDataTexture(cuArray);
float* angle_sin = new float[dims.iProjAngles];
float* angle_cos = new float[dims.iProjAngles];
for (unsigned int i = 0; i < dims.iProjAngles; ++i) {
angle_sin[i] = sinf(angles[i]);
angle_cos[i] = cosf(angles[i]);
}
cudaError_t e1 = cudaMemcpyToSymbol(gC_angle_sin, angle_sin, dims.iProjAngles*sizeof(float), 0, cudaMemcpyHostToDevice);
cudaError_t e2 = cudaMemcpyToSymbol(gC_angle_cos, angle_cos, dims.iProjAngles*sizeof(float), 0, cudaMemcpyHostToDevice);
assert(e1 == cudaSuccess);
assert(e2 == cudaSuccess);
delete[] angle_sin;
delete[] angle_cos;
dim3 dimBlock(g_volBlockX, g_volBlockY);
dim3 dimGrid(((dims.iVolX+g_volBlockX-1)/g_volBlockX)*((dims.iVolY+g_volBlockY-1)/g_volBlockY), (dims.iVolZ+g_volBlockZ-1)/g_volBlockZ);
// timeval t;
// tic(t);
for (unsigned int i = 0; i < dims.iProjAngles; i += g_anglesPerBlock) {
devBP_FDK<<>>(D_volumeData.ptr, D_volumeData.pitch/sizeof(float), i, fSrcOrigin, fDetOrigin, fSrcZ, fDetZ, 1.0f / fDetUSize, 1.0f / fDetVSize, dims);
}
cudaTextForceKernelsCompletion();
cudaFreeArray(cuArray);
// printf("%f\n", toc(t));
return true;
}
__global__ void devFDK_preweight(void* D_projData, unsigned int projPitch, unsigned int startAngle, unsigned int endAngle, float fSrcOrigin, float fDetOrigin, float fSrcZ, float fDetZ, float fDetUSize, float fDetVSize, const SDimensions3D dims)
{
float* projData = (float*)D_projData;
int angle = startAngle + blockIdx.y * g_anglesPerWeightBlock + threadIdx.y;
if (angle >= endAngle)
return;
const int detectorU = (blockIdx.x%((dims.iProjU+g_detBlockU-1)/g_detBlockU)) * g_detBlockU + threadIdx.x;
const int startDetectorV = (blockIdx.x/((dims.iProjU+g_detBlockU-1)/g_detBlockU)) * g_detBlockV;
int endDetectorV = startDetectorV + g_detBlockV;
if (endDetectorV > dims.iProjV)
endDetectorV = dims.iProjV;
// We need the length of the central ray and the length of the ray(s) to
// our detector pixel(s).
const float fCentralRayLength = fSrcOrigin + fDetOrigin;
const float fU = (detectorU - 0.5f*dims.iProjU + 0.5f) * fDetUSize;
const float fT = fCentralRayLength * fCentralRayLength + fU * fU;
float fV = (startDetectorV - 0.5f*dims.iProjV + 0.5f) * fDetVSize + fDetZ - fSrcZ;
for (int detectorV = startDetectorV; detectorV < endDetectorV; ++detectorV)
{
const float fRayLength = sqrtf(fT + fV * fV);
const float fWeight = fCentralRayLength / fRayLength;
projData[(detectorV*dims.iProjAngles+angle)*projPitch+detectorU] *= fWeight;
fV += 1.0f;
}
}
__global__ void devFDK_ParkerWeight(void* D_projData, unsigned int projPitch, unsigned int startAngle, unsigned int endAngle, float fSrcOrigin, float fDetOrigin, float fSrcZ, float fDetZ, float fDetUSize, float fCentralFanAngle, const SDimensions3D dims)
{
float* projData = (float*)D_projData;
int angle = startAngle + blockIdx.y * g_anglesPerWeightBlock + threadIdx.y;
if (angle >= endAngle)
return;
const int detectorU = (blockIdx.x%((dims.iProjU+g_detBlockU-1)/g_detBlockU)) * g_detBlockU + threadIdx.x;
const int startDetectorV = (blockIdx.x/((dims.iProjU+g_detBlockU-1)/g_detBlockU)) * g_detBlockV;
int endDetectorV = startDetectorV + g_detBlockV;
if (endDetectorV > dims.iProjV)
endDetectorV = dims.iProjV;
// We need the length of the central ray and the length of the projection
// of our ray onto the central slice
const float fCentralRayLength = fSrcOrigin + fDetOrigin;
// TODO: Detector pixel size
const float fU = (detectorU - 0.5f*dims.iProjU + 0.5f) * fDetUSize;
//const float fGamma = atanf(fU / fCentralRayLength);
//const float fBeta = gC_angle[angle];
const float fGamma = atanf(fU / fCentralRayLength);
float fBeta = -gC_angle[angle];
if (fBeta < 0.0f)
fBeta += 2*M_PI;
if (fBeta >= 2*M_PI)
fBeta -= 2*M_PI;
// compute the weight depending on the location in the central fan's radon
// space
float fWeight;
if (fBeta <= 0.0f) {
fWeight = 0.0f;
} else if (fBeta <= 2.0f*(fCentralFanAngle + fGamma)) {
fWeight = sinf((M_PI / 4.0f) * fBeta / (fCentralFanAngle + fGamma));
fWeight *= fWeight;
} else if (fBeta <= M_PI + 2*fGamma) {
fWeight = 1.0f;
} else if (fBeta <= M_PI + 2*fCentralFanAngle) {
fWeight = sinf((M_PI / 4.0f) * (M_PI + 2.0f*fCentralFanAngle - fBeta) / (fCentralFanAngle - fGamma));
fWeight *= fWeight;
} else {
fWeight = 0.0f;
}
for (int detectorV = startDetectorV; detectorV < endDetectorV; ++detectorV)
{
projData[(detectorV*dims.iProjAngles+angle)*projPitch+detectorU] *= fWeight;
}
}
// Perform the FDK pre-weighting and filtering
bool FDK_PreWeight(cudaPitchedPtr D_projData,
float fSrcOrigin, float fDetOrigin,
float fSrcZ, float fDetZ,
float fDetUSize, float fDetVSize, bool bShortScan,
const SDimensions3D& dims, const float* angles)
{
// The pre-weighting factor for a ray is the cosine of the angle between
// the central line and the ray.
dim3 dimBlock(g_detBlockU, g_anglesPerWeightBlock);
dim3 dimGrid( ((dims.iProjU+g_detBlockU-1)/g_detBlockU)*((dims.iProjV+g_detBlockV-1)/g_detBlockV),
(dims.iProjAngles+g_anglesPerWeightBlock-1)/g_anglesPerWeightBlock);
int projPitch = D_projData.pitch/sizeof(float);
devFDK_preweight<<>>(D_projData.ptr, projPitch, 0, dims.iProjAngles, fSrcOrigin, fDetOrigin, fSrcZ, fDetZ, fDetUSize, fDetVSize, dims);
cudaTextForceKernelsCompletion();
if (bShortScan) {
// We do short-scan Parker weighting
cudaError_t e1 = cudaMemcpyToSymbol(gC_angle, angles,
dims.iProjAngles*sizeof(float), 0,
cudaMemcpyHostToDevice);
assert(!e1);
// TODO: detector pixel size!
float fCentralFanAngle = atanf((dims.iProjU*0.5f) /
(fSrcOrigin + fDetOrigin));
devFDK_ParkerWeight<<>>(D_projData.ptr, projPitch, 0, dims.iProjAngles, fSrcOrigin, fDetOrigin, fSrcZ, fDetZ, fDetUSize, fCentralFanAngle, dims);
}
cudaTextForceKernelsCompletion();
return true;
}
bool FDK_Filter(cudaPitchedPtr D_projData,
cufftComplex * D_filter,
float fSrcOrigin, float fDetOrigin,
float fSrcZ, float fDetZ,
float fDetUSize, float fDetVSize, bool bShortScan,
const SDimensions3D& dims, const float* angles)
{
// The filtering is a regular ramp filter per detector line.
int iPaddedDetCount = calcNextPowerOfTwo(2 * dims.iProjU);
int iHalfFFTSize = calcFFTFourSize(iPaddedDetCount);
int projPitch = D_projData.pitch/sizeof(float);
// We process one sinogram at a time.
float* D_sinoData = (float*)D_projData.ptr;
cufftComplex * D_sinoFFT = NULL;
allocateComplexOnDevice(dims.iProjAngles, iHalfFFTSize, &D_sinoFFT);
bool ok = true;
for (int v = 0; v < dims.iProjV; ++v) {
ok = runCudaFFT(dims.iProjAngles, D_sinoData, projPitch,
dims.iProjU, iPaddedDetCount, iHalfFFTSize,
D_sinoFFT);
if (!ok) break;
applyFilter(dims.iProjAngles, iHalfFFTSize, D_sinoFFT, D_filter);
ok = runCudaIFFT(dims.iProjAngles, D_sinoFFT, D_sinoData, projPitch,
dims.iProjU, iPaddedDetCount, iHalfFFTSize);
if (!ok) break;
D_sinoData += (dims.iProjAngles * projPitch);
}
freeComplexOnDevice(D_sinoFFT);
return ok;
}
bool FDK(cudaPitchedPtr D_volumeData,
cudaPitchedPtr D_projData,
float fSrcOrigin, float fDetOrigin,
float fSrcZ, float fDetZ, float fDetUSize, float fDetVSize,
const SDimensions3D& dims, const float* angles, bool bShortScan)
{
bool ok;
// Generate filter
// TODO: Check errors
cufftComplex * D_filter;
int iPaddedDetCount = calcNextPowerOfTwo(2 * dims.iProjU);
int iHalfFFTSize = calcFFTFourSize(iPaddedDetCount);
ok = FDK_PreWeight(D_projData, fSrcOrigin, fDetOrigin,
fSrcZ, fDetZ, fDetUSize, fDetVSize,
bShortScan, dims, angles);
if (!ok)
return false;
cufftComplex *pHostFilter = new cufftComplex[dims.iProjAngles * iHalfFFTSize];
memset(pHostFilter, 0, sizeof(cufftComplex) * dims.iProjAngles * iHalfFFTSize);
genFilter(FILTER_RAMLAK, 1.0f, dims.iProjAngles, pHostFilter, iPaddedDetCount, iHalfFFTSize);
allocateComplexOnDevice(dims.iProjAngles, iHalfFFTSize, &D_filter);
uploadComplexArrayToDevice(dims.iProjAngles, iHalfFFTSize, pHostFilter, D_filter);
delete [] pHostFilter;
// Perform filtering
ok = FDK_Filter(D_projData, D_filter, fSrcOrigin, fDetOrigin,
fSrcZ, fDetZ, fDetUSize, fDetVSize,
bShortScan, dims, angles);
// Clean up filter
freeComplexOnDevice(D_filter);
if (!ok)
return false;
// Perform BP
ok = FDK_BP(D_volumeData, D_projData, fSrcOrigin, fDetOrigin, fSrcZ, fDetZ,
fDetUSize, fDetVSize, dims, angles);
if (!ok)
return false;
processVol3D(D_volumeData,
(M_PI / 2.0f) / (float)dims.iProjAngles, dims);
return true;
}
}
#ifdef STANDALONE
void dumpVolume(const char* filespec, const cudaPitchedPtr& data, const SDimensions3D& dims, float fMin, float fMax)
{
float* buf = new float[dims.iVolX*dims.iVolY];
unsigned int pitch = data.pitch / sizeof(float);
for (int i = 0; i < dims.iVolZ; ++i) {
cudaMemcpy2D(buf, dims.iVolX*sizeof(float), ((float*)data.ptr)+pitch*dims.iVolY*i, data.pitch, dims.iVolX*sizeof(float), dims.iVolY, cudaMemcpyDeviceToHost);
char fname[512];
sprintf(fname, filespec, dims.iVolZ-i-1);
saveImage(fname, dims.iVolY, dims.iVolX, buf, fMin, fMax);
}
}
void dumpSinograms(const char* filespec, const cudaPitchedPtr& data, const SDimensions3D& dims, float fMin, float fMax)
{
float* bufs = new float[dims.iProjAngles*dims.iProjU];
unsigned int pitch = data.pitch / sizeof(float);
for (int i = 0; i < dims.iProjV; ++i) {
cudaMemcpy2D(bufs, dims.iProjU*sizeof(float), ((float*)data.ptr)+pitch*dims.iProjAngles*i, data.pitch, dims.iProjU*sizeof(float), dims.iProjAngles, cudaMemcpyDeviceToHost);
char fname[512];
sprintf(fname, filespec, i);
saveImage(fname, dims.iProjAngles, dims.iProjU, bufs, fMin, fMax);
}
}
void dumpProjections(const char* filespec, const cudaPitchedPtr& data, const SDimensions3D& dims, float fMin, float fMax)
{
float* bufp = new float[dims.iProjV*dims.iProjU];
unsigned int pitch = data.pitch / sizeof(float);
for (int i = 0; i < dims.iProjAngles; ++i) {
for (int j = 0; j < dims.iProjV; ++j) {
cudaMemcpy(bufp+dims.iProjU*j, ((float*)data.ptr)+pitch*dims.iProjAngles*j+pitch*i, dims.iProjU*sizeof(float), cudaMemcpyDeviceToHost);
}
char fname[512];
sprintf(fname, filespec, i);
saveImage(fname, dims.iProjV, dims.iProjU, bufp, fMin, fMax);
}
}
int main()
{
#if 0
SDimensions3D dims;
dims.iVolX = 512;
dims.iVolY = 512;
dims.iVolZ = 512;
dims.iProjAngles = 180;
dims.iProjU = 1024;
dims.iProjV = 1024;
dims.iRaysPerDet = 1;
cudaExtent extentV;
extentV.width = dims.iVolX*sizeof(float);
extentV.height = dims.iVolY;
extentV.depth = dims.iVolZ;
cudaPitchedPtr volData; // pitch, ptr, xsize, ysize
cudaMalloc3D(&volData, extentV);
cudaExtent extentP;
extentP.width = dims.iProjU*sizeof(float);
extentP.height = dims.iProjAngles;
extentP.depth = dims.iProjV;
cudaPitchedPtr projData; // pitch, ptr, xsize, ysize
cudaMalloc3D(&projData, extentP);
cudaMemset3D(projData, 0, extentP);
#if 0
float* slice = new float[256*256];
cudaPitchedPtr ptr;
ptr.ptr = slice;
ptr.pitch = 256*sizeof(float);
ptr.xsize = 256*sizeof(float);
ptr.ysize = 256;
for (unsigned int i = 0; i < 256*256; ++i)
slice[i] = 1.0f;
for (unsigned int i = 0; i < 256; ++i) {
cudaExtent extentS;
extentS.width = dims.iVolX*sizeof(float);
extentS.height = dims.iVolY;
extentS.depth = 1;
cudaPos sp = { 0, 0, 0 };
cudaPos dp = { 0, 0, i };
cudaMemcpy3DParms p;
p.srcArray = 0;
p.srcPos = sp;
p.srcPtr = ptr;
p.dstArray = 0;
p.dstPos = dp;
p.dstPtr = volData;
p.extent = extentS;
p.kind = cudaMemcpyHostToDevice;
cudaMemcpy3D(&p);
#if 0
if (i == 128) {
for (unsigned int j = 0; j < 256*256; ++j)
slice[j] = 0.0f;
}
#endif
}
#endif
SConeProjection angle[180];
angle[0].fSrcX = -1536;
angle[0].fSrcY = 0;
angle[0].fSrcZ = 0;
angle[0].fDetSX = 1024;
angle[0].fDetSY = -512;
angle[0].fDetSZ = 512;
angle[0].fDetUX = 0;
angle[0].fDetUY = 1;
angle[0].fDetUZ = 0;
angle[0].fDetVX = 0;
angle[0].fDetVY = 0;
angle[0].fDetVZ = -1;
#define ROTATE0(name,i,alpha) do { angle[i].f##name##X = angle[0].f##name##X * cos(alpha) - angle[0].f##name##Y * sin(alpha); angle[i].f##name##Y = angle[0].f##name##X * sin(alpha) + angle[0].f##name##Y * cos(alpha); } while(0)
for (int i = 1; i < 180; ++i) {
angle[i] = angle[0];
ROTATE0(Src, i, i*2*M_PI/180);
ROTATE0(DetS, i, i*2*M_PI/180);
ROTATE0(DetU, i, i*2*M_PI/180);
ROTATE0(DetV, i, i*2*M_PI/180);
}
#undef ROTATE0
astraCUDA3d::ConeFP(volData, projData, dims, angle, 1.0f);
//dumpSinograms("sino%03d.png", projData, dims, 0, 512);
//dumpProjections("proj%03d.png", projData, dims, 0, 512);
astraCUDA3d::zeroVolumeData(volData, dims);
float* angles = new float[dims.iProjAngles];
for (int i = 0; i < 180; ++i)
angles[i] = i*2*M_PI/180;
astraCUDA3d::FDK(volData, projData, 1536, 512, 0, 0, dims, angles);
dumpVolume("vol%03d.png", volData, dims, -20, 100);
#else
SDimensions3D dims;
dims.iVolX = 1000;
dims.iVolY = 999;
dims.iVolZ = 500;
dims.iProjAngles = 376;
dims.iProjU = 1024;
dims.iProjV = 524;
dims.iRaysPerDet = 1;
float* angles = new float[dims.iProjAngles];
for (int i = 0; i < dims.iProjAngles; ++i)
angles[i] = -i*(M_PI)/360;
cudaPitchedPtr volData = astraCUDA3d::allocateVolumeData(dims);
cudaPitchedPtr projData = astraCUDA3d::allocateProjectionData(dims);
astraCUDA3d::zeroProjectionData(projData, dims);
astraCUDA3d::zeroVolumeData(volData, dims);
timeval t;
tic(t);
for (int i = 0; i < dims.iProjAngles; ++i) {
char fname[256];
sprintf(fname, "/home/wpalenst/tmp/Elke/proj%04d.png", i);
unsigned int w,h;
float* bufp = loadImage(fname, w,h);
int pitch = projData.pitch / sizeof(float);
for (int j = 0; j < dims.iProjV; ++j) {
cudaMemcpy(((float*)projData.ptr)+dims.iProjAngles*pitch*j+pitch*i, bufp+dims.iProjU*j, dims.iProjU*sizeof(float), cudaMemcpyHostToDevice);
}
delete[] bufp;
}
printf("Load time: %f\n", toc(t));
//dumpSinograms("sino%03d.png", projData, dims, -8.0f, 256.0f);
//astraCUDA3d::FDK(volData, projData, 7350, 62355, 0, 10, dims, angles);
//astraCUDA3d::FDK(volData, projData, 7350, -380, 0, 10, dims, angles);
tic(t);
astraCUDA3d::FDK(volData, projData, 7383.29867, 0, 0, 10, dims, angles);
printf("FDK time: %f\n", toc(t));
tic(t);
dumpVolume("vol%03d.png", volData, dims, -65.9f, 200.0f);
//dumpVolume("vol%03d.png", volData, dims, 0.0f, 256.0f);
printf("Save time: %f\n", toc(t));
#endif
}
#endif