com.idrsolutions.image.jpeg2000.Trns Maven / Gradle / Ivy
/*
* ===========================================
* Java Pdf Extraction Decoding Access Library
* ===========================================
*
* Project Info: http://www.idrsolutions.com
* Help section for developers at http://www.idrsolutions.com/support/
*
* (C) Copyright 1997-2015 IDRsolutions and Contributors.
*
* This file is part of JPedal/JPDF2HTML5
*
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* ---------------
* Trns.java
* ---------------
*/
package com.idrsolutions.image.jpeg2000;
import java.util.List;
/**
* Class performs inverse discrete wavelet transformation in JPEG2000 data
*/
public class Trns {
private static final float alpha = -1.5861343421f;
private static final float beta = -0.0529801186f;
private static final float gamma = 0.8829110755f;
private static final float delta = 0.4435068520f;
private static final float zeta = 1.2301741049f;
private static final float zeta_ = 1.0f / zeta;
private final boolean reversible;
public Trns(boolean reversible) {
this.reversible = reversible;
}
public SubbandCoefficient getInversed(List subCos, int u0, int v0) {
SubbandCoefficient sb = subCos.get(0);
for (int i = 1; i < subCos.size(); i++) {
sb = getNext(sb, subCos.get(i), u0, v0);
}
return sb;
}
private static void applyFilter(float[] data, int offset, int size, boolean reversible) {
int aa = offset - 1, bb = offset + 1;
int cc = offset + size - 2, dd = offset + size;
data[aa--] = data[bb++];
data[dd++] = data[cc--];
data[aa--] = data[bb++];
data[dd++] = data[cc--];
data[aa--] = data[bb++];
data[dd++] = data[cc--];
data[aa] = data[bb];
data[dd] = data[cc];
int len = size >> 1;
if (reversible) {
int n = len;
int j = offset;
while (n >= 0) {
data[j] -= ((int) (data[j - 1] + data[j + 1] + 2)) >> 2;
j += 2;
n--;
}
n = len - 1;
j = offset + 1;
while (n >= 0) {
data[j] += ((int) (data[j - 1] + data[j + 1])) >> 1;
j += 2;
n--;
}
} else {
float current, next;
int j = offset - 3;
for (int n = len + 4; n > 0; n--, j += 2) {
data[j] *= zeta_;
}
j = offset - 2;
current = delta * data[j - 1];
int n = len + 2;
while (n >= 0) {
next = delta * data[j + 1];
data[j] = zeta * data[j] - current - next;
n--;
if (n >= 0) {
j += 2;
current = delta * data[j + 1];
data[j] = zeta * data[j] - current - next;
} else {
break;
}
j += 2;
n--;
}
j = offset - 1;
current = gamma * data[j - 1];
n = len + 1;
while (n >= 0) {
next = gamma * data[j + 1];
data[j] -= current + next;
n--;
if (n >= 0) {
j += 2;
current = gamma * data[j + 1];
data[j] -= current + next;
} else {
break;
}
j += 2;
n--;
}
j = offset;
current = beta * data[j - 1];
n = len;
while (n >= 0) {
next = beta * data[j + 1];
data[j] -= current + next;
n--;
if (n >= 0) {
j += 2;
current = beta * data[j + 1];
data[j] -= current + next;
} else {
break;
}
j += 2;
n--;
}
if (len != 0) {
j = offset + 1;
current = alpha * data[j - 1];
n = len - 1;
while (n >= 0) {
next = alpha * data[j + 1];
data[j] -= current + next;
n--;
if (n >= 0) {
j += 2;
current = alpha * data[j + 1];
data[j] -= current + next;
} else {
break;
}
j += 2;
n--;
}
}
}
}
private SubbandCoefficient getNext(SubbandCoefficient ll, SubbandCoefficient other, int u0, int v0) {
int widthLL = ll.width;
int heightLL = ll.height;
int width = other.width;
int height = other.height;
// float[] ff = other.floatItems;
int k = 0;
for (int i = 0; i < heightLL; i++) {
int l = i * 2 * width;
for (int j = 0; j < widthLL; j++) {
other.floatItems[l] = ll.floatItems[k];
k++;
l += 2;
}
}
int bufferPadding = 4;
float[] rowBuffer = new float[width + 2 * bufferPadding];
if (width == 1) {
if ((u0 & 1) != 0) {
k = 0;
for (int v = 0; v < height; v++) {
other.floatItems[k] *= 0.5;
k += width;
}
}
} else {
k = 0;
for (int v = 0; v < height; v++) {
System.arraycopy(other.floatItems, k, rowBuffer, bufferPadding, width);
applyFilter(rowBuffer, bufferPadding, width, reversible);
System.arraycopy(rowBuffer, bufferPadding, other.floatItems, k, width);
k += width;
}
}
int numBuffers = 16;
float[][] colBuffers = new float[numBuffers][height + 2 * bufferPadding];
int currentBuffer = 0;
int ss = bufferPadding + height;
if (height == 1) {
if ((v0 & 1) != 0) {
for (int u = 0; u < width; u++) {
other.floatItems[u] *= 0.5;
}
}
} else {
for (int u = 0; u < width; u++) {
if (currentBuffer == 0) {
numBuffers = Math.min(width - u, numBuffers);
k = u;
for (int l = bufferPadding; l < ss; l++) {
for (int b = 0; b < numBuffers; b++) {
colBuffers[b][l] = other.floatItems[k + b];
}
k += width;
}
currentBuffer = numBuffers;
}
currentBuffer--;
float[] buffer = colBuffers[currentBuffer];
applyFilter(buffer, bufferPadding, height, reversible);
if (currentBuffer == 0) {
k = u - numBuffers + 1;
for (int l = bufferPadding; l < ss; k += width, l++) {
for (int b = 0; b < numBuffers; b++) {
other.floatItems[k + b] = colBuffers[b][l];
}
}
}
}
}
SubbandCoefficient sc = new SubbandCoefficient();
sc.width = width;
sc.height = height;
sc.floatItems = other.floatItems;
return sc;
}
}
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