Bicubic interpolation is one of the common interpolation method, but I can not find any working implementation on OpenCL. I was decided to write bicubic interpolation on OpenCL myself, but ...
I have some problem with kernel programm.
When I run kernel execution, program failed with error开发者_运维百科 CL_EXEC_STATUS_ERROR_FOR_EVENTS_IN_WAIT_LIST. No any other information about cause of error. I am using javacl binding form google code: http://code.google.com/p/javacl, AMD Accelerated Parallel Processing SDK 2.3 on Ubuntu linux 10.10, hardware AMD Radeon 5xxxHD
I haven`t opencl debugger on ubuntu for AMD APP SDK (
If I uncomment float4 val=read_imagef(signal, sampler, (float2)(x+iX,y+iY)); and comment calculation of bicubic interpolation "float4 val=..." all work without any error(but using bilinear interpolation). I think that this error because of invalid memory access or register memory overflow.
const sampler_t sampler = CLK_NORMALIZED_COORDS_FALSE | CLK_FILTER_LINEAR | CLK_ADDRESS_CLAMP_TO_EDGE;
const float CATMULL_ROM[16]={-0.5F,1.5F,-1.5F,0.5F,1.0F,-2.5F,2.0F,-0.5F,-0.5F,0.0F,0.5F,0.0F,0.0F,1.0F,0.0F,0.0F};
__kernel void bicubicUpscale(int scale,read_only image2d_t signal, write_only image2d_t upscale) {
int x = get_global_id(0)-2, y = get_global_id(1)-2;
float C[16];
float T[16];
for (int i = 0; i < 16; i++)
{
C[i]=0.0F;
T[i]=0.0F;
}
for (int i = 0; i < 4; i++)
for (int j = 0; j < 4; j++)
for (int k = 0; k < 4; k++)
{
T[4*i+j] += read_imagef(signal, sampler, (int2)(x+k,y+i)).x * CATMULL_ROM[4*j+k];
}
for (int i = 0; i < 4; i++)
for (int j = 0; j < 4; j++)
for (int k = 0; k < 4; k++)
{
C[4*i+j] += CATMULL_ROM[4*i+k] * T[4*k+j];
}
for (int i = 0; i < scale; i++)
{
for (int j = 0; j < scale; j++)
{
float iX=(float)j/(float) scale;
float iY=(float)i/(float) scale;
//float4 val=read_imagef(signal, sampler, (float2)(x+iX,y+iY));
float val= iX * (iX * (iX * (iY * (iY * (iY * C[0] + C[1]) + C[2]) + C[3])
+ (iY * (iY * (iY * C[4] + C[5]) + C[6]) + C[7]))
+ (iY * (iY * (iY * C[8] + C[9]) + C[10]) + C[11]))
+ (iY * (iY * (iY * C[12] + C[13]) + C[14]) + C[15]);
write_imagef(upscale, (int2)(x*scale+j, y*scale+i), val);
}
}
}
I rewrite this program for using local memory, but it still not working correctly
const sampler_t sampler = CLK_NORMALIZED_COORDS_FALSE | CLK_FILTER_LINEAR | CLK_ADDRESS_CLAMP_TO_EDGE;
const float CATMULL_ROM[]={-0.5F,1.5F,-1.5F,0.5F,1.0F,-2.5F,2.0F,-0.5F,-0.5F,0.0F,0.5F,0.0F,0.0F,1.0F,0.0F,0.0F};
__kernel void bicubicUpscale(local float* sharedBuffer,int scale,read_only image2d_t signal, write_only image2d_t upscale) {
int x = get_global_id(0)-2, y = get_global_id(1)-2;
//int locX=get_local_id(0);
int offsetT = (y+2)*512+(x+2)*32+16;
int offsetC = (y+2)*512+(x+2)*32;
global float* C=&sharedBuffer[offsetT];
global float* T=&sharedBuffer[offsetT];
for (int i = 0; i < 32; i++){
sharedBuffer[offsetC+ i]=0.0F;
}
for (int i = 0; i < 4; i++)
for (int j = 0; j < 4; j++)
for (int k = 0; k < 4; k++){
//T[4*i+j] = mad(read_imagef(signal, sampler, (int2)(x+k,y+i)).x,CATMULL_ROM[4*j+k],T[4*i+j]);
T[i+j] += read_imagef(signal, sampler, (int2)(x+k,y+i)).x * CATMULL_ROM[4*j+k];
}
for (int i = 0; i < 4; i++)
for (int j = 0; j < 4; j++)
for (int k = 0; k < 4; k++){
//C[4*i+j] = mad(CATMULL_ROM[4*i+k],T[4*k+j],C[4*i+j]);
sharedBuffer[offsetC +4*i+j] += CATMULL_ROM[4*i+k] * sharedBuffer[offsetT + 4*k+j];
}
barrier (CLK_GLOBAL_MEM_FENCE);
for (int i = 0; i < scale; i++)
for (int j = 0; j < scale; j++)
{
float iX=(float)j/(float) scale;
float iY=(float)i/(float) scale;
float4 val= iX * (iX * (iX * (iY * (iY * (iY * C[0] + C[1]) + C[2]) + C[3])
+ (iY * (iY * (iY * C[4] + C[5]) + C[6]) + C[7]))
+ (iY * (iY * (iY * C[8] + C[9]) + C[10]) + C[11]))
+ (iY * (iY * (iY * C[12] + C[13]) + C[14]) + C[15]);
write_imagef(upscale, (int2)(x*scale+j, y*scale+i), val);
}
}
Do you know any decision for this problem.
Java sources + maven2 build. Use command "mvn clean compile exec:java" to compile and run demo.
Regards, Igor
I am fix it! This kernel is not optimal in performance point of view, but functional correct.
Please use such parameters for enqueueNDRange:
kernelBicubic.getKernel().setArgs(scaleFactor, inImage, imageOut);
lastEvent=kernelBicubic.getKernel().enqueueNDRange(queue,
new int[]{(int) inImage.getWidth()+1,(int) inImage.getHeight()+1},lastEvent);
Kernel code:
const sampler_t sampler = CLK_NORMALIZED_COORDS_FALSE | CLK_FILTER_LINEAR | CLK_ADDRESS_CLAMP_TO_EDGE;
const float CATMULL_ROM[16]={-0.5F, 1.5F,-1.5F, 0.5F, 1.0F,-2.5F, 2.0F,-0.5F,-0.5F, 0.0F, 0.5F, 0.0F, 0.0F, 1.0F, 0.0F, 0.0F};
inlie float calcT(image2d_t signal,int x,int y,int i,int j){
return read_imagef(signal, sampler, (int2)(x ,y+i)).x * CATMULL_ROM[4*j]
+read_imagef(signal, sampler, (int2)(x+1,y+i)).x * CATMULL_ROM[4*j+1]
+read_imagef(signal, sampler, (int2)(x+2,y+i)).x * CATMULL_ROM[4*j+2]
+read_imagef(signal, sampler, (int2)(x+3,y+i)).x * CATMULL_ROM[4*j+3];
}
inline float C(image2d_t signal,int x,int y,int i,int j){
return CATMULL_ROM[4*i ] * calcT(signal,x,y,0,j)
+CATMULL_ROM[4*i+1] * calcT(signal,x,y,1,j)
+CATMULL_ROM[4*i+2] * calcT(signal,x,y,2,j)
+CATMULL_ROM[4*i+3] * calcT(signal,x,y,3,j);
}
__kernel void bicubicUpscale(int scale,read_only image2d_t signal, write_only image2d_t upscale) {
int x = get_global_id(0)-2, y = get_global_id(1)-2;
float C0 =C(signal,x,y,0,0);
float C1 =C(signal,x,y,0,1);
float C2 =C(signal,x,y,0,2);
float C3 =C(signal,x,y,0,3);
float C4 =C(signal,x,y,1,0);
float C5 =C(signal,x,y,1,1);
float C6 =C(signal,x,y,1,2);
float C7 =C(signal,x,y,1,3);
float C8 =C(signal,x,y,2,0);
float C9 =C(signal,x,y,2,1);
float C10=C(signal,x,y,2,2);
float C11=C(signal,x,y,2,3);
float C12=C(signal,x,y,3,0);
float C13=C(signal,x,y,3,1);
float C14=C(signal,x,y,3,2);
float C15=C(signal,x,y,3,3);
float xOff=scale*1.5F + x*scale;
float yOff=scale*1.5F + y*scale;
for (int i = 0; i < scale; i++)
{
for (int j = 0; j < scale; j++)
{
float iY=(float)j/(float) scale;
float iX=(float)i/(float) scale;
float val= iX * (iX * (iX * (iY * (iY * (iY * C0 + C1) + C2) + C3)
+ (iY * (iY * (iY * C4 + C5) + C6) + C7))
+ (iY * (iY * (iY * C8 + C9) + C10) + C11))
+ (iY * (iY * (iY * C12 + C13) + C14) + C15);
write_imagef(upscale, (int2)(xOff+j, yOff+i), val);
}
}
}
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