com.idrsolutions.image.jpeg.DCT 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
*
* ---------------
* DCT.java
* ---------------
*/
package com.idrsolutions.image.jpeg;
/**
*
*/
public class DCT {
/**
* Method performs fastest discrete cosine transform conversion with 64
* length array with integer multiplications
*
* @param inp
* @param code
*/
public static void FDCTQ(final int[] inp, int code) {
int x0, x1, x2, x3, x4, x5, x6, x7, x8;
for (int i = 0; i < 8; i++) {
int ii = i << 3;
x0 = inp[ii];
x1 = inp[ii + 1];
x2 = inp[ii + 2];
x3 = inp[ii + 3];
x4 = inp[ii + 4];
x5 = inp[ii + 5];
x6 = inp[ii + 6];
x7 = inp[ii + 7];
if ((x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7) == 0) {
continue;
}
x8 = x7 + x0;
x0 -= x7;
x7 = x1 + x6;
x1 -= x6;
x6 = x2 + x5;
x2 -= x5;
x5 = x3 + x4;
x3 -= x4;
x4 = x8 + x5;
x8 -= x5;
x5 = x7 + x6;
x7 -= x6;
x6 = 0x3ec * (x1 + x2);
x2 = -1204 * x2 + x6;
x1 = -804 * x1 + x6;
x6 = 0x353 * (x0 + x3);
x3 = -1420 * x3 + x6;
x0 = -282 * x0 + x6;
x6 = x4 + x5;
x4 -= x5;
x5 = 0x22a * (x7 + x8);
x7 = -1891 * x7 + x5;
x8 = 783 * x8 + x5;
x5 = x0 + x2;
x0 -= x2;
x2 = x3 + x1;
x3 -= x1;
inp[ii] = x6;
inp[ii + 1] = (x2 + x5) >> 10;
inp[ii + 2] = x8 >> 10;
inp[ii + 3] = (x3 * 0xb5) >> 17;
inp[ii + 4] = x4;
inp[ii + 5] = (x0 * 0xb5) >> 17;
inp[ii + 6] = x7 >> 10;
inp[ii + 7] = (x2 - x5) >> 10;
}
for (int i = 0; i < 8; i++) {
x0 = inp[i];
x1 = inp[8 + i];
x2 = inp[16 + i];
x3 = inp[24 + i];
x4 = inp[32 + i];
x5 = inp[40 + i];
x6 = inp[48 + i];
x7 = inp[56 + i];
if ((x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7) == 0) {
continue;
}
x8 = x7 + x0;
x0 -= x7;
x7 = x1 + x6;
x1 -= x6;
x6 = x2 + x5;
x2 -= x5;
x5 = x3 + x4;
x3 -= x4;
x4 = x8 + x5;
x8 -= x5;
x5 = x7 + x6;
x7 -= x6;
x6 = 0x3ec * (x1 + x2);
x2 = -1204 * x2 + x6;
x1 = -804 * x1 + x6;
x6 = 0x353 * (x0 + x3);
x3 = -1420 * x3 + x6;
x0 = -282 * x0 + x6;
x6 = x4 + x5;
x4 -= x5;
x5 = 0x22a * (x7 + x8);
x7 = -1891 * x7 + x5;
x8 = 783 * x8 + x5;
x5 = x0 + x2;
x0 -= x2;
x2 = x3 + x1;
x3 -= x1;
inp[i] = (x6 + 16) >> 3;
inp[8 + i] = (x2 + x5 + 0x4000) >> 13;
inp[16 + i] = (x8 + 0x4000) >> 13;
inp[24 + i] = ((x3 >> 8) * 0xb5 + 0x2000) >> 12;
inp[32 + i] = (x4 + 16) >> 3;
inp[40 + i] = ((x0 >> 8) * 0xb5 + 0x2000) >> 12;
inp[48 + i] = (x7 + 0x4000) >> 13;
inp[56 + i] = (x2 - x5 + 0x4000) >> 13;
}
if (code == 0) {
for (int i = 0; i < 64; i++) {
inp[i] = ((inp[i] * JpegLUT.IDLD100[i] + 268433408) >> 12) - 65535;
}
} else {
for (int i = 0; i < 64; i++) {
inp[i] = ((inp[i] * JpegLUT.IDCD100[i] + 268433408) >> 12) - 65535;
}
}
// old 100% method
// the lookup table can be generated by dividing 1 by ql and qc table values
// if (code == 0) {
// for (int i = 0; i < 64; i++) {
// inp[i] = (int) ((inp[i] * JpegLUT.DLD100[i]) + 65535.5) - 65535;
// }
// } else {
// for (int i = 0; i < 64; i++) {
// inp[i] = (int) ((inp[i] * JpegLUT.DCD100[i]) + 65535.5) - 65535;
// }
// }
}
public static void IDCTQ(Component component, int offset) {
int[] p = new int[64];
int[] qt = component.qTable;
int[] inp = component.codeBlock;
int v0, v1, v2, v3, v4, v5, v6, v7;
int p0, p1, p2, p3, p4, p5, p6, p7;
int t,temp;
for (int row = 0; row < 64; row += 8) {
temp = offset + row;
p0 = inp[temp];
p1 = inp[temp + 1];
p2 = inp[temp + 2];
p3 = inp[temp + 3];
p4 = inp[temp + 4];
p5 = inp[temp + 5];
p6 = inp[temp + 6];
p7 = inp[temp + 7];
p0 *= qt[row];
if ((p1 | p2 | p3 | p4 | p5 | p6 | p7) == 0) {
t = (5793 * p0 + 512) >> 10;
p[row] = t;
p[row + 1] = t;
p[row + 2] = t;
p[row + 3] = t;
p[row + 4] = t;
p[row + 5] = t;
p[row + 6] = t;
p[row + 7] = t;
continue;
}
p1 *= qt[row + 1];
p2 *= qt[row + 2];
p3 *= qt[row + 3];
p4 *= qt[row + 4];
p5 *= qt[row + 5];
p6 *= qt[row + 6];
p7 *= qt[row + 7];
v0 = (5793 * p0 + 128) >> 8;
v1 = (5793 * p4 + 128) >> 8;
v4 = (2896 * (p1 - p7) + 128) >> 8;
v7 = (2896 * (p1 + p7) + 128) >> 8;
v5 = p3 << 4;
v6 = p5 << 4;
v0 = (v0 + v1 + 1) >> 1;
v1 = v0 - v1;
t = (p2 * 3784 + p6 * 1567 + 128) >> 8;
v2 = (p2 * 1567 - p6 * 3784 + 128) >> 8;
v4 = (v4 + v6 + 1) >> 1;
v6 = v4 - v6;
v7 = (v7 + v5 + 1) >> 1;
v5 = v7 - v5;
v0 = (v0 + t + 1) >> 1;
v3 = v0 - t;
v1 = (v1 + v2 + 1) >> 1;
v2 = v1 - v2;
t = (v4 * 2276 + v7 * 3406 + 2048) >> 12;
v4 = (v4 * 3406 - v7 * 2276 + 2048) >> 12;
v7 = t;
t = (v5 * 799 + v6 * 4017 + 2048) >> 12;
v5 = (v5 * 4017 - v6 * 799 + 2048) >> 12;
p[row] = v0 + v7;
p[row + 7] = v0 - v7;
p[row + 1] = v1 + t;
p[row + 6] = v1 - t;
p[row + 2] = v2 + v5;
p[row + 5] = v2 - v5;
p[row + 3] = v3 + v4;
p[row + 4] = v3 - v4;
}
for (int col = 0; col < 8; ++col) {
p0 = p[col];
p1 = p[col + 8];
p2 = p[col + 16];
p3 = p[col + 24];
p4 = p[col + 32];
p5 = p[col + 40];
p6 = p[col + 48];
p7 = p[col + 56];
if ((p1 | p2 | p3 | p4 | p5 | p6 | p7) == 0) {
t = (5793 * p0 + 8192) >> 14;
t = (t < -2040) ? 0 : (t >= 2024) ? 255 : (t + 2056) >> 4;
inp[offset + col] = t;
inp[offset + col + 8] = t;
inp[offset + col + 16] = t;
inp[offset + col + 24] = t;
inp[offset + col + 32] = t;
inp[offset + col + 40] = t;
inp[offset + col + 48] = t;
inp[offset + col + 56] = t;
continue;
}
v0 = (5793 * p0 + 2048) >> 12;
v1 = (5793 * p4 + 2048) >> 12;
v4 = (2896 * (p1 - p7) + 2048) >> 12;
v7 = (2896 * (p1 + p7) + 2048) >> 12;
v0 = ((v0 + v1 + 1) >> 1) + 4112;
v1 = v0 - v1;
t = (p2 * 3784 + p6 * 1567 + 2048) >> 12;
v2 = (p2 * 1567 - p6 * 3784 + 2048) >> 12;
v3 = t;
v4 = (v4 + p5 + 1) >> 1;
v6 = v4 - p5;
v7 = (v7 + p3 + 1) >> 1;
v5 = v7 - p3;
v0 = (v0 + v3 + 1) >> 1;
v3 = v0 - v3;
v1 = (v1 + v2 + 1) >> 1;
v2 = v1 - v2;
t = (v4 * 2276 + v7 * 3406 + 2048) >> 12;
v4 = (v4 * 3406 - v7 * 2276 + 2048) >> 12;
v7 = t;
t = (v5 * 799 + v6 * 4017 + 2048) >> 12;
v5 = (v5 * 4017 - v6 * 799 + 2048) >> 12;
p0 = v0 + v7;
p7 = v0 - v7;
p1 = v1 + t;
p6 = v1 - t;
p2 = v2 + v5;
p5 = v2 - v5;
p3 = v3 + v4;
p4 = v3 - v4;
p0 = (p0 < 16) ? 0 : (p0 >= 4080) ? 255 : p0 >> 4;
p1 = (p1 < 16) ? 0 : (p1 >= 4080) ? 255 : p1 >> 4;
p2 = (p2 < 16) ? 0 : (p2 >= 4080) ? 255 : p2 >> 4;
p3 = (p3 < 16) ? 0 : (p3 >= 4080) ? 255 : p3 >> 4;
p4 = (p4 < 16) ? 0 : (p4 >= 4080) ? 255 : p4 >> 4;
p5 = (p5 < 16) ? 0 : (p5 >= 4080) ? 255 : p5 >> 4;
p6 = (p6 < 16) ? 0 : (p6 >= 4080) ? 255 : p6 >> 4;
p7 = (p7 < 16) ? 0 : (p7 >= 4080) ? 255 : p7 >> 4;
temp = offset + col;
inp[temp] = p0;
inp[temp + 8] = p1;
inp[temp + 16] = p2;
inp[temp + 24] = p3;
inp[temp + 32] = p4;
inp[temp + 40] = p5;
inp[temp + 48] = p6;
inp[temp + 56] = p7;
}
}
}
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