matrix downsampling C
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I have a 1280x720 buffered matrix and i would like to implement a downsampling method which take one sample each 9 in both directions.
For example:
122222221222222212222222122222221222222221222222221.......
111111.....
so i implement this method:
int16_t* resample(int16_t *in_b){
int scale=9,W=1280,H=720;
int w=W/scale;
int h=H/scale;
int16_t *out_b=(int16_t*)malloc(w*h*sizeof(int16_t));
for (i=0;i<h;i++){
for (j=0;j<w;j++){
out_b[i*w+j]=in_b[(i*W*scale)+(j*scale)];
}
}
return out_b;
}
but if i draw an heatmap of the output it shows that input is repeated twice, what i'm wrong?
c image-processing resampling
asked Nov 22 '18 at 21:30
sdrabbsdrabb
77211
add a comment |
I have a 1280x720 buffered matrix and i would like to implement a downsampling method which take one sample each 9 in both directions.
For example:
122222221222222212222222122222221222222221222222221.......
111111.....
so i implement this method:
int16_t* resample(int16_t *in_b){
int scale=9,W=1280,H=720;
int w=W/scale;
int h=H/scale;
int16_t *out_b=(int16_t*)malloc(w*h*sizeof(int16_t));
for (i=0;i<h;i++){
for (j=0;j<w;j++){
out_b[i*w+j]=in_b[(i*W*scale)+(j*scale)];
}
}
return out_b;
}
but if i draw an heatmap of the output it shows that input is repeated twice, what i'm wrong?
c image-processing resampling
asked Nov 22 '18 at 21:30
sdrabbsdrabb
77211
1
I don’t think you’re doing anything wrong.
– Cris Luengo
Nov 23 '18 at 2:12
...not in the code you exposed. (At least, I cannot see something wrong.) May be, the error happens anywhere else or it's the correct result you just didn't expect.
– Scheff
Nov 23 '18 at 6:52
add a comment |
I have a 1280x720 buffered matrix and i would like to implement a downsampling method which take one sample each 9 in both directions.
For example:
122222221222222212222222122222221222222221222222221.......
111111.....
so i implement this method:
int16_t* resample(int16_t *in_b){
int scale=9,W=1280,H=720;
int w=W/scale;
int h=H/scale;
int16_t *out_b=(int16_t*)malloc(w*h*sizeof(int16_t));
for (i=0;i<h;i++){
for (j=0;j<w;j++){
out_b[i*w+j]=in_b[(i*W*scale)+(j*scale)];
}
}
return out_b;
}
but if i draw an heatmap of the output it shows that input is repeated twice, what i'm wrong?
c image-processing resampling
asked Nov 22 '18 at 21:30
sdrabbsdrabb
77211
I have a 1280x720 buffered matrix and i would like to implement a downsampling method which take one sample each 9 in both directions.
For example:
122222221222222212222222122222221222222221222222221.......
111111.....
so i implement this method:
int16_t* resample(int16_t *in_b){
int scale=9,W=1280,H=720;
int w=W/scale;
int h=H/scale;
int16_t *out_b=(int16_t*)malloc(w*h*sizeof(int16_t));
for (i=0;i<h;i++){
for (j=0;j<w;j++){
out_b[i*w+j]=in_b[(i*W*scale)+(j*scale)];
}
}
return out_b;
}
but if i draw an heatmap of the output it shows that input is repeated twice, what i'm wrong?
c image-processing resampling
c image-processing resampling
asked Nov 22 '18 at 21:30
sdrabbsdrabb
77211
asked Nov 22 '18 at 21:30
sdrabbsdrabb
77211
asked Nov 22 '18 at 21:30
sdrabbsdrabb
77211
asked Nov 22 '18 at 21:30
sdrabbsdrabb
77211
asked Nov 22 '18 at 21:30
sdrabbsdrabb
77211
77211
1
I don’t think you’re doing anything wrong.
– Cris Luengo
Nov 23 '18 at 2:12
...not in the code you exposed. (At least, I cannot see something wrong.) May be, the error happens anywhere else or it's the correct result you just didn't expect.
– Scheff
Nov 23 '18 at 6:52
add a comment |
1
I don’t think you’re doing anything wrong.
– Cris Luengo
Nov 23 '18 at 2:12
...not in the code you exposed. (At least, I cannot see something wrong.) May be, the error happens anywhere else or it's the correct result you just didn't expect.
– Scheff
Nov 23 '18 at 6:52
1
1
I don’t think you’re doing anything wrong.
– Cris Luengo
Nov 23 '18 at 2:12
I don’t think you’re doing anything wrong.
– Cris Luengo
Nov 23 '18 at 2:12
...not in the code you exposed. (At least, I cannot see something wrong.) May be, the error happens anywhere else or it's the correct result you just didn't expect.
– Scheff
Nov 23 '18 at 6:52
...not in the code you exposed. (At least, I cannot see something wrong.) May be, the error happens anywhere else or it's the correct result you just didn't expect.
– Scheff
Nov 23 '18 at 6:52
add a comment |
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1
I don’t think you’re doing anything wrong.
– Cris Luengo
Nov 23 '18 at 2:12
...not in the code you exposed. (At least, I cannot see something wrong.) May be, the error happens anywhere else or it's the correct result you just didn't expect.
– Scheff
Nov 23 '18 at 6:52