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/*
* Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* FUNCTION
* mlib_ImageConvKernelConvert - Convert convolution kernel from
* floating point version to integer
* version.
*
* SYNOPSIS
* mlib_status mlib_ImageConvKernelConvert(mlib_s32 *ikernel,
* mlib_s32 *iscale,
* const mlib_d64 *fkernel,
* mlib_s32 m,
* mlib_s32 n,
* mlib_type type);
*
* ARGUMENT
* ikernel integer kernel
* iscale scaling factor of the integer kernel
* fkernel floating-point kernel
* m width of the convolution kernel
* n height of the convolution kernel
* type image type
*
* DESCRIPTION
* Convert a floating point convolution kernel to integer kernel
* with scaling factor. The result integer kernel and scaling factor
* can be used in convolution functions directly without overflow.
*
* RESTRICTION
* The type can be MLIB_BYTE, MLIB_SHORT, MLIB_USHORT or MLIB_INT.
*/
#include <stdlib.h>
#include "mlib_image.h"
#include "mlib_SysMath.h"
#include "mlib_ImageConv.h"
/***************************************************************/
#ifdef __sparc
#define CLAMP_S32(dst, src) \
dst = (mlib_s32)(src)
#else
#define CLAMP_S32(dst, src) { \
mlib_d64 s0 = (mlib_d64)(src); \
if (s0 > (mlib_d64)MLIB_S32_MAX) s0 = (mlib_d64)MLIB_S32_MAX; \
if (s0 < (mlib_d64)MLIB_S32_MIN) s0 = (mlib_d64)MLIB_S32_MIN; \
dst = (mlib_s32)s0; \
}
#endif /* __sparc */
/***************************************************************/
mlib_status mlib_ImageConvKernelConvert(mlib_s32 *ikernel,
mlib_s32 *iscale,
const mlib_d64 *fkernel,
mlib_s32 m,
mlib_s32 n,
mlib_type type)
{
mlib_d64 sum_pos, sum_neg, sum, norm, max, f;
mlib_s32 isum_pos, isum_neg, isum, test;
mlib_s32 i, scale, scale1, chk_flag;
if (ikernel == NULL || iscale == NULL || fkernel == NULL || m < 1 || n < 1) {
return MLIB_FAILURE;
}
if ((type == MLIB_BYTE) || (type == MLIB_SHORT) || (type == MLIB_USHORT)) {
if (type != MLIB_SHORT) { /* MLIB_BYTE, MLIB_USHORT */
sum_pos = 0;
sum_neg = 0;
for (i = 0; i < m * n; i++) {
if (fkernel[i] > 0)
sum_pos += fkernel[i];
else
sum_neg -= fkernel[i];
}
sum = (sum_pos > sum_neg) ? sum_pos : sum_neg;
scale = mlib_ilogb(sum);
scale++;
scale = 31 - scale;
}
else { /* MLIB_SHORT */
sum = 0;
max = 0;
for (i = 0; i < m * n; i++) {
f = mlib_fabs(fkernel[i]);
sum += f;
max = (max > f) ? max : f;
}
scale1 = mlib_ilogb(max) + 1;
scale = mlib_ilogb(sum);
scale = (scale > scale1) ? scale : scale1;
scale++;
scale = 32 - scale;
}
if (scale <= 16)
return MLIB_FAILURE;
if (scale > 31)
scale = 31;
*iscale = scale;
chk_flag = mlib_ImageConvVersion(m, n, scale, type);
if (!chk_flag) {
norm = (1u << scale);
for (i = 0; i < m * n; i++) {
CLAMP_S32(ikernel[i], fkernel[i] * norm);
}
return MLIB_SUCCESS;
}
/* try to round coefficients */
#ifdef __sparc
scale1 = 16; /* shift of coefficients is 16 */
#else
if (chk_flag == 3)
scale1 = 16; /* MMX */
else
scale1 = (type == MLIB_BYTE) ? 8 : 16;
#endif /* __sparc */
norm = (1u << (scale - scale1));
for (i = 0; i < m * n; i++) {
if (fkernel[i] > 0)
ikernel[i] = (mlib_s32) (fkernel[i] * norm + 0.5);
else
ikernel[i] = (mlib_s32) (fkernel[i] * norm - 0.5);
}
isum_pos = 0;
isum_neg = 0;
test = 0;
for (i = 0; i < m * n; i++) {
if (ikernel[i] > 0)
isum_pos += ikernel[i];
else
isum_neg -= ikernel[i];
}
if (type == MLIB_BYTE || type == MLIB_USHORT) {
isum = (isum_pos > isum_neg) ? isum_pos : isum_neg;
if (isum >= (1 << (31 - scale1)))
test = 1;
}
else {
isum = isum_pos + isum_neg;
if (isum >= (1 << (32 - scale1)))
test = 1;
for (i = 0; i < m * n; i++) {
if (abs(ikernel[i]) >= (1 << (31 - scale1)))
test = 1;
}
}
if (test == 1) { /* rounding according scale1 cause overflow, truncate instead of round */
for (i = 0; i < m * n; i++)
ikernel[i] = (mlib_s32) (fkernel[i] * norm) << scale1;
}
else { /* rounding is Ok */
for (i = 0; i < m * n; i++)
ikernel[i] = ikernel[i] << scale1;
}
return MLIB_SUCCESS;
}
else if ((type == MLIB_INT) || (type == MLIB_BIT)) {
max = 0;
for (i = 0; i < m * n; i++) {
f = mlib_fabs(fkernel[i]);
max = (max > f) ? max : f;
}
scale = mlib_ilogb(max);
if (scale > 29)
return MLIB_FAILURE;
if (scale < -100)
scale = -100;
*iscale = 29 - scale;
scale = 29 - scale;
norm = 1.0;
while (scale > 30) {
norm *= (1 << 30);
scale -= 30;
}
norm *= (1 << scale);
for (i = 0; i < m * n; i++) {
if (fkernel[i] > 0) {
CLAMP_S32(ikernel[i], fkernel[i] * norm + 0.5);
}
else {
CLAMP_S32(ikernel[i], fkernel[i] * norm - 0.5);
}
}
return MLIB_SUCCESS;
}
else {
return MLIB_FAILURE;
}
}
/***************************************************************/