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By : catagranic
Date : October 28 2020, 08:00 PM
hope this fix your issue What version of java (java -version) and OS are you using? It might be a bug in the transform (which has since been fixed) or it might be an error in the rendering to PNG.
Have you tried using a NEAREST_NEIGHBOR filter instead of the BILINEAR one? code : ## Bilinear Interpolation on large arrays in Java

By : user3640874
Date : March 29 2020, 07:55 AM
wish of those help That's what the InterpolationBilinear class is supposed to do. See the documentation. The only thing it does is implement bilinear interpolation between four points arranged in a rectangle. The formula is explained here, and you can also implement it yourself pretty easily.
The question is: what are float x and float y in your example? For InterpolationBilinear.interpolate they're supposed to represent the fractional position between the four corners of the sample rectangle. ## Bilinear interpolation of 2d data using c / awk / shell

By : mythri gm
Date : March 29 2020, 07:55 AM
Does that help (Edited to allow for the Moving Target.)
The following works on your (very limited!) sample data set. It works like this:
code :
``````#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_ITEM    25

struct data_t {
int row;
int col;
int data;
} array[MAX_ITEM];

int n_item = 0;

// interpolate A > B
//             v   v
//             C > D
void interpolate (int A, int B, int C, int D)
{
int i,j, deltaCol,deltaRow;
float a,b, delta_AC, delta_BD, value;

a = array[A].data;
b = array[B].data;

deltaCol = 2*(array[B].col-array[A].col);
deltaRow = 5*(array[C].row-array[A].row);

delta_AC = (array[C].data-array[A].data)/(float)deltaRow;
delta_BD = (array[D].data-array[B].data)/(float)deltaRow;

// rows
for (j=0; j<=deltaRow; j++)
{
// columns
for (i=0; i<=deltaCol; i++)
{
if (j % 5)
printf ("%.1f ", array[A].row+(j/5.0f));
else
printf ("%d ", array[A].row+j/5);
if (i % 2)
printf ("%.1f ", array[A].col+(i/2.0f));
else
printf ("%d ", array[A].col+i/2);

value = a+(b-a)*((float)i/deltaCol);
if ((int)(100*value+0.5) % 100)
printf ("%.1f\n", value);
else
printf ("%d\n", (int)(value+0.5f));

}
a += delta_AC;
b += delta_BD;
}
}

// For a start row/col A find B,C,D
// where B = A(0,>=1), C=A(>=1,0), D=A(>=1,>=1)
void interpolate_from (int A)
{
int i, B=-1, C=-1, D=-1;

for (i=0; i<n_item; i++)
{
if (i == A) continue;
if (array[A].row == array[i].row)
{
if (array[A].col < array[i].col || (B != -1 && array[i].col < array[B].col))
{
B = i;
}
} else
if (array[A].row < array[i].row)
{
if (array[A].col == array[i].col)
{
C = i;
} else
{
if (array[A].col < array[i].col || (D != -1 && array[i].col < array[D].col))
{
D = i;
}
}
}
if (B+1 && C+1 && D+1)
{
interpolate (A,B,C,D);
return;
}
}

}

int main (void)
{
int i,j,k;
FILE *f;

f = fopen ("data.txt", "r");
while (n_item < MAX_ITEM && fscanf (f, "%d %d %d", &i,&j, &k) == 3)
{
array[n_item].row = i;
array[n_item].col = j;
array[n_item].data = k;
n_item++;
}
fclose (f);

for (i=0; i<n_item; i++)
interpolate_from (i);

printf ("\n");
return 0;
}
``````
``````20 14 91
21 14 162
21 18 95
20 18 210
``````
``````20 14 91
20 14.5 105.9
20 15 120.8
20 15.5 135.6
...
`````` ## Error when doing bilinear interpolation with `interp2 {pracma}`; any better way for 2D interpolation?

By : Hari Krishna
Date : March 29 2020, 07:55 AM
To fix this issue I am trying to perform 2d interpolation on a table named vol_coarse. , If I don't get you wrong, you want:
code :
``````x <- c(3 / 8, 1 / 2, 3 / 4, 1, 1 + 1 / 2, 2, 3, 6)  ## V1
y <- c(2.4, 2.6, 2.8)  ## column names
Z <- cbind(c(0.50, 0.59, 0.66, 0.71, 0.75, 0.78, 0.82, 0.87),  ## V2
c(0.48, 0.57, 0.64, 0.69, 0.73, 0.76, 0.80, 0.85),  ## V3
c(0.44, 0.53, 0.60, 0.65, 0.69, 0.72, 0.76, 0.81))  ## V4
xp <- 3 / 4
yp <- 2.70
``````
``````persp(x, y, Z)
image(x, y, Z)
contour(x, y, Z)
``````
``````library(fields)
## the list MUST has name `x`, `y`, `x`!
## i.e., unnamed list `list(x, y, Z)` does not work!
interp.surface(list(x = x, y = y, z = Z), cbind(xp, yp))
#  0.62
``````
``````## from manual

Z: numeric ‘length(x)’-by-‘length(y)’ matrix.

## from source code of `interp2`

lx <- length(x)
ly <- length(y)
if (ncol(Z) != lx || nrow(Z) != ly)
stop("Required: 'length(x) = ncol(Z)' and 'length(y) = nrow(Z)'.")
``````
``````interp2(x, y, t(Z), xp, yp)
#  0.62
``````
``````interp2(y, x, Z, yp, xp)
#  0.62
`````` ## Bilinear Interpolation Byte Rollover Java

By : Kerrigan Fairbairn
Date : March 29 2020, 07:55 AM
like below fixes the issue The actual process is this:
The pixel value is sampled as an unsigned byte The bytes (assumed to be signed) are interpolated The interpolated value is than used in the destination image as an unsigned byte
code :
``````float lerp(byte x1, byte x2, float a) {

return unsignedByteToInt(x1) * (1 - a) + unsignedByteToInt(x2) * a;

}

int unsignedByteToInt(byte x) {return (((int) x) + 255) % 255;}
`````` ## Error with Bilinear interpolation implementation

By : Charles Samuel Lasis
Date : March 29 2020, 07:55 AM
Hope that helps There are many syntactic errors in this piece of code. First of all, you're using pointers for x, y and val and you don't dereference them, but pass them by value to functions like cvFloor() and Mat::at() as if they were local variables - this cannot work and every call to these functions right now will give you a conversion error during compilation.
The same goes for this line:
code :
``````val = ((1/( (x2-x1)*(y2-y1) ) ) *(q11*(x2-x)*(y2-y)+q21*(x2-x1)*(y2-
y) +q12*(x2-x)*(y-y1)+q22*(x-x1)*(y-y1)));
`````` 