public static FloatMatrix conv2d(FloatMatrix input, FloatMatrix kernel, Type type) {
FloatMatrix xShape = new FloatMatrix(1, 2);
xShape.put(0, input.rows);
xShape.put(1, input.columns);
FloatMatrix yShape = new FloatMatrix(1, 2);
yShape.put(0, kernel.rows);
yShape.put(1, kernel.columns);
FloatMatrix zShape = xShape.add(yShape).sub(1);
int retRows = (int) zShape.get(0);
int retCols = (int) zShape.get(1);
ComplexFloatMatrix fftInput = complexDisceteFourierTransform(input, retRows, retCols);
ComplexFloatMatrix fftKernel = complexDisceteFourierTransform(kernel, retRows, retCols);
ComplexFloatMatrix mul = fftKernel.mul(fftInput);
ComplexFloatMatrix retComplex = complexInverseDisceteFourierTransform(mul);
FloatMatrix ret = retComplex.getReal();
if (type == Type.VALID) {
FloatMatrix validShape = xShape.subi(yShape).add(1);
FloatMatrix start = zShape.sub(validShape).div(2);
FloatMatrix end = start.add(validShape);
if (start.get(0) < 1 || start.get(1) < 1)
throw new IllegalStateException("Illegal row index " + start);
if (end.get(0) < 1 || end.get(1) < 1)
throw new IllegalStateException("Illegal column index " + end);
ret =
ret.get(
RangeUtils.interval((int) start.get(0), (int) end.get(0)),
RangeUtils.interval((int) start.get(1), (int) end.get(1)));
}
return ret;
}
