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Commit 747088ea authored by Davis King's avatar Davis King
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Added save_jpeg()

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dlib/external/libjpeg/jfdctint.cpp 0 → 100644
View file @ 747088ea
/*
* jfdctint.c
*
* Copyright (C) 1991-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains a slow-but-accurate integer implementation of the
* forward DCT (Discrete Cosine Transform).
*
* A 2-D DCT can be done by 1-D DCT on each row followed by 1-D DCT
* on each column. Direct algorithms are also available, but they are
* much more complex and seem not to be any faster when reduced to code.
*
* This implementation is based on an algorithm described in
* C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT
* Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics,
* Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991.
* The primary algorithm described there uses 11 multiplies and 29 adds.
* We use their alternate method with 12 multiplies and 32 adds.
* The advantage of this method is that no data path contains more than one
* multiplication; this allows a very simple and accurate implementation in
* scaled fixed-point arithmetic, with a minimal number of shifts.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jdct.h" /* Private declarations for DCT subsystem */
#ifdef DCT_ISLOW_SUPPORTED
/*
* This module is specialized to the case DCTSIZE = 8.
*/
#if DCTSIZE != 8
Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
#endif
/*
* The poop on this scaling stuff is as follows:
*
* Each 1-D DCT step produces outputs which are a factor of sqrt(N)
* larger than the true DCT outputs. The final outputs are therefore
* a factor of N larger than desired; since N=8 this can be cured by
* a simple right shift at the end of the algorithm. The advantage of
* this arrangement is that we save two multiplications per 1-D DCT,
* because the y0 and y4 outputs need not be divided by sqrt(N).
* In the IJG code, this factor of 8 is removed by the quantization step
* (in jcdctmgr.c), NOT in this module.
*
* We have to do addition and subtraction of the integer inputs, which
* is no problem, and multiplication by fractional constants, which is
* a problem to do in integer arithmetic. We multiply all the constants
* by CONST_SCALE and convert them to integer constants (thus retaining
* CONST_BITS bits of precision in the constants). After doing a
* multiplication we have to divide the product by CONST_SCALE, with proper
* rounding, to produce the correct output. This division can be done
* cheaply as a right shift of CONST_BITS bits. We postpone shifting
* as long as possible so that partial sums can be added together with
* full fractional precision.
*
* The outputs of the first pass are scaled up by PASS1_BITS bits so that
* they are represented to better-than-integral precision. These outputs
* require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word
* with the recommended scaling. (For 12-bit sample data, the intermediate
* array is long anyway.)
*
* To avoid overflow of the 32-bit intermediate results in pass 2, we must
* have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis
* shows that the values given below are the most effective.
*/
#if BITS_IN_JSAMPLE == 8
#define CONST_BITS 13
#define PASS1_BITS 2
#else
#define CONST_BITS 13
#define PASS1_BITS 1 /* lose a little precision to avoid overflow */
#endif
/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
* causing a lot of useless floating-point operations at run time.
* To get around this we use the following pre-calculated constants.
* If you change CONST_BITS you may want to add appropriate values.
* (With a reasonable C compiler, you can just rely on the FIX() macro...)
*/
#if CONST_BITS == 13
#define FIX_0_298631336 ((long) 2446) /* FIX(0.298631336) */
#define FIX_0_390180644 ((long) 3196) /* FIX(0.390180644) */
#define FIX_0_541196100 ((long) 4433) /* FIX(0.541196100) */
#define FIX_0_765366865 ((long) 6270) /* FIX(0.765366865) */
#define FIX_0_899976223 ((long) 7373) /* FIX(0.899976223) */
#define FIX_1_175875602 ((long) 9633) /* FIX(1.175875602) */
#define FIX_1_501321110 ((long) 12299) /* FIX(1.501321110) */
#define FIX_1_847759065 ((long) 15137) /* FIX(1.847759065) */
#define FIX_1_961570560 ((long) 16069) /* FIX(1.961570560) */
#define FIX_2_053119869 ((long) 16819) /* FIX(2.053119869) */
#define FIX_2_562915447 ((long) 20995) /* FIX(2.562915447) */
#define FIX_3_072711026 ((long) 25172) /* FIX(3.072711026) */
#else
#define FIX_0_298631336 FIX(0.298631336)
#define FIX_0_390180644 FIX(0.390180644)
#define FIX_0_541196100 FIX(0.541196100)
#define FIX_0_765366865 FIX(0.765366865)
#define FIX_0_899976223 FIX(0.899976223)
#define FIX_1_175875602 FIX(1.175875602)
#define FIX_1_501321110 FIX(1.501321110)
#define FIX_1_847759065 FIX(1.847759065)
#define FIX_1_961570560 FIX(1.961570560)
#define FIX_2_053119869 FIX(2.053119869)
#define FIX_2_562915447 FIX(2.562915447)
#define FIX_3_072711026 FIX(3.072711026)
#endif
/* Multiply an long variable by an long constant to yield an long result.
* For 8-bit samples with the recommended scaling, all the variable
* and constant values involved are no more than 16 bits wide, so a
* 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
* For 12-bit samples, a full 32-bit multiplication will be needed.
*/
#if BITS_IN_JSAMPLE == 8
#define MULTIPLY(var,const) MULTIPLY16C16(var,const)
#else
#define MULTIPLY(var,const) ((var) * (const))
#endif
/*
* Perform the forward DCT on one block of samples.
*/
GLOBAL(void)
jpeg_fdct_islow (DCTELEM * data)
{
long tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
long tmp10, tmp11, tmp12, tmp13;
long z1, z2, z3, z4, z5;
DCTELEM *dataptr;
int ctr;
SHIFT_TEMPS
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
dataptr = data;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
tmp0 = dataptr[0] + dataptr[7];
tmp7 = dataptr[0] - dataptr[7];
tmp1 = dataptr[1] + dataptr[6];
tmp6 = dataptr[1] - dataptr[6];
tmp2 = dataptr[2] + dataptr[5];
tmp5 = dataptr[2] - dataptr[5];
tmp3 = dataptr[3] + dataptr[4];
tmp4 = dataptr[3] - dataptr[4];
/* Even part per LL&M figure 1 --- note that published figure is faulty;
* rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
*/
tmp10 = tmp0 + tmp3;
tmp13 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp1 - tmp2;
dataptr[0] = (DCTELEM) ((tmp10 + tmp11) << PASS1_BITS);
dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);
z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
dataptr[2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),
CONST_BITS-PASS1_BITS);
dataptr[6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
CONST_BITS-PASS1_BITS);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
* cK represents cos(K*pi/16).
* i0..i3 in the paper are tmp4..tmp7 here.
*/
z1 = tmp4 + tmp7;
z2 = tmp5 + tmp6;
z3 = tmp4 + tmp6;
z4 = tmp5 + tmp7;
z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
tmp4 = MULTIPLY(tmp4, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
tmp5 = MULTIPLY(tmp5, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
tmp6 = MULTIPLY(tmp6, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
tmp7 = MULTIPLY(tmp7, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
z3 += z5;
z4 += z5;
dataptr[7] = (DCTELEM) DESCALE(tmp4 + z1 + z3, CONST_BITS-PASS1_BITS);
dataptr[5] = (DCTELEM) DESCALE(tmp5 + z2 + z4, CONST_BITS-PASS1_BITS);
dataptr[3] = (DCTELEM) DESCALE(tmp6 + z2 + z3, CONST_BITS-PASS1_BITS);
dataptr[1] = (DCTELEM) DESCALE(tmp7 + z1 + z4, CONST_BITS-PASS1_BITS);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
*/
dataptr = data;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
tmp7 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
tmp6 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
tmp5 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
tmp4 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
/* Even part per LL&M figure 1 --- note that published figure is faulty;
* rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
*/
tmp10 = tmp0 + tmp3;
tmp13 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp1 - tmp2;
dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp11, PASS1_BITS);
dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp10 - tmp11, PASS1_BITS);
z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
CONST_BITS+PASS1_BITS);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
* cK represents cos(K*pi/16).
* i0..i3 in the paper are tmp4..tmp7 here.
*/
z1 = tmp4 + tmp7;
z2 = tmp5 + tmp6;
z3 = tmp4 + tmp6;
z4 = tmp5 + tmp7;
z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
tmp4 = MULTIPLY(tmp4, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
tmp5 = MULTIPLY(tmp5, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
tmp6 = MULTIPLY(tmp6, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
tmp7 = MULTIPLY(tmp7, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
z3 += z5;
z4 += z5;
dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp4 + z1 + z3,
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp5 + z2 + z4,
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp6 + z2 + z3,
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp7 + z1 + z4,
CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
}
#endif /* DCT_ISLOW_SUPPORTED */
dlib/image_io.h
View file @ 747088ea
...@@ -9,6 +9,7 @@ ...@@ -9,6 +9,7 @@
#include "image_loader/load_image.h" #include "image_loader/load_image.h"
#include "image_saver/image_saver.h" #include "image_saver/image_saver.h"
#include "image_saver/save_png.h" #include "image_saver/save_png.h"
#include "image_saver/save_jpeg.h"
#endif // DLIB_IMAGe_IO_ #endif // DLIB_IMAGe_IO_
dlib/image_saver/save_jpeg.cpp 0 → 100644
View file @ 747088ea
// Copyright (C) 2014 Davis E. King (davis@dlib.net), Nils Labugt
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_JPEG_SAVER_CPp_
#define DLIB_JPEG_SAVER_CPp_
// only do anything with this file if DLIB_JPEG_SUPPORT is defined
#ifdef DLIB_JPEG_SUPPORT
#include "../array2d.h"
#include "../pixel.h"
#include "save_jpeg.h"
#include <stdio.h>
#include <jpeglib.h>
#include <sstream>
#include <setjmp.h>
#include "image_saver.h"
namespace dlib
{
// ----------------------------------------------------------------------------------------
struct jpeg_saver_error_mgr
{
jpeg_error_mgr pub; /* "public" fields */
jmp_buf setjmp_buffer; /* for return to caller */
};
void jpeg_saver_error_exit (j_common_ptr cinfo)
{
/* cinfo->err really points to a jpeg_saver_error_mgr struct, so coerce pointer */
jpeg_saver_error_mgr* myerr = (jpeg_saver_error_mgr*) cinfo->err;
/* Return control to the setjmp point */
longjmp(myerr->setjmp_buffer, 1);
}
// ----------------------------------------------------------------------------------------
void save_jpeg (
const array2d<rgb_pixel>& img,
const std::string& filename,
int quality
)
{
FILE* outfile = fopen(filename.c_str(), "wb");
if (!outfile)
throw image_save_error("Can't open file " + filename + " for writing.");
jpeg_compress_struct cinfo;
jpeg_saver_error_mgr jerr;
cinfo.err = jpeg_std_error(&jerr.pub);
jerr.pub.error_exit = jpeg_saver_error_exit;
/* Establish the setjmp return context for my_error_exit to use. */
if (setjmp(jerr.setjmp_buffer))
{
/* If we get here, the JPEG code has signaled an error.
* We need to clean up the JPEG object, close the input file, and return.
*/
jpeg_destroy_compress(&cinfo);
fclose(outfile);
throw image_save_error("save_jpeg: error while writing " + filename);
}
jpeg_create_compress(&cinfo);
jpeg_stdio_dest(&cinfo, outfile);
cinfo.image_width = img.nc();
cinfo.image_height = img.nr();
cinfo.input_components = 3;
cinfo.in_color_space = JCS_RGB;
jpeg_set_defaults(&cinfo);
jpeg_set_quality (&cinfo, quality, true);
jpeg_start_compress(&cinfo, true);
// now write out the rows one at a time
while (cinfo.next_scanline < cinfo.image_height) {
JSAMPROW row_pointer = (JSAMPROW) &img[cinfo.next_scanline][0];
jpeg_write_scanlines(&cinfo, &row_pointer, 1);
}
jpeg_finish_compress(&cinfo);
jpeg_destroy_compress(&cinfo);
fclose( outfile );
}
// ----------------------------------------------------------------------------------------
void save_jpeg (
const array2d<unsigned char>& img,
const std::string& filename,
int quality
)
{
FILE* outfile = fopen(filename.c_str(), "wb");
if (!outfile)
throw image_save_error("Can't open file " + filename + " for writing.");
jpeg_compress_struct cinfo;
jpeg_saver_error_mgr jerr;
cinfo.err = jpeg_std_error(&jerr.pub);
jerr.pub.error_exit = jpeg_saver_error_exit;
/* Establish the setjmp return context for my_error_exit to use. */
if (setjmp(jerr.setjmp_buffer))
{
/* If we get here, the JPEG code has signaled an error.
* We need to clean up the JPEG object, close the input file, and return.
*/
jpeg_destroy_compress(&cinfo);
fclose(outfile);
throw image_save_error("save_jpeg: error while writing " + filename);
}
jpeg_create_compress(&cinfo);
jpeg_stdio_dest(&cinfo, outfile);
cinfo.image_width = img.nc();
cinfo.image_height = img.nr();
cinfo.input_components = 1;
cinfo.in_color_space = JCS_GRAYSCALE;
jpeg_set_defaults(&cinfo);
jpeg_set_quality (&cinfo, quality, true);
jpeg_start_compress(&cinfo, true);
// now write out the rows one at a time
while (cinfo.next_scanline < cinfo.image_height) {
JSAMPROW row_pointer = (JSAMPROW) &img[cinfo.next_scanline][0];
jpeg_write_scanlines(&cinfo, &row_pointer, 1);
}
jpeg_finish_compress(&cinfo);
jpeg_destroy_compress(&cinfo);
fclose( outfile );
}
// ----------------------------------------------------------------------------------------
}
#endif // DLIB_JPEG_SUPPORT
#endif // DLIB_JPEG_SAVER_CPp_
dlib/image_saver/save_jpeg.h 0 → 100644
View file @ 747088ea
// Copyright (C) 2014 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_SAVE_JPEG_Hh_
#define DLIB_SAVE_JPEG_Hh_
#include "save_jpeg_abstract.h"
#include "../enable_if.h"
#include "../matrix.h"
#include "../array2d.h"
#include "../pixel.h"
#include "../image_processing/generic_image.h"
#include <string>
namespace dlib
{
// ----------------------------------------------------------------------------------------
void save_jpeg (
const array2d<rgb_pixel>& img,
const std::string& filename,
int quality = 75
);
// ----------------------------------------------------------------------------------------
void save_jpeg (
const array2d<unsigned char>& img,
const std::string& filename,
int quality = 75
);
// ----------------------------------------------------------------------------------------
template <
typename image_type
>
typename disable_if<is_matrix<image_type> >::type save_jpeg(
const image_type& img,
const std::string& filename,
int quality = 75
)
{
// Convert any kind of grayscale image to an unsigned char image
if (pixel_traits<typename image_traits<image_type>::pixel_type>::grayscale)
{
array2d<unsigned char> temp;
assign_image(temp, img);
save_jpeg(temp, filename, quality);
}
else
{
// This is some other kind of color image so just save it as an RGB image.
array2d<rgb_pixel> temp;
assign_image(temp, img);
save_jpeg(temp, filename, quality);
}
}
// ----------------------------------------------------------------------------------------
template <
typename EXP
>
void save_jpeg(
const matrix_exp<EXP>& img,
const std::string& file_name,
int quality = 75
)
{
array2d<typename EXP::type> temp;
assign_image(temp, img);
save_jpeg(temp, file_name, quality);
}
// ----------------------------------------------------------------------------------------
}
#endif // DLIB_SAVE_JPEG_Hh_
dlib/image_saver/save_jpeg_abstract.h 0 → 100644
View file @ 747088ea
// Copyright (C) 2014 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#undef DLIB_SAVE_JPEG_ABSTRACT_Hh_
#ifdef DLIB_SAVE_JPEG_ABSTRACT_Hh_
#include "../image_processing/generic_image.h"
#include "../pixel.h"
#include <string>
namespace dlib
{
// ----------------------------------------------------------------------------------------
template <
typename image_type
>
void save_jpeg (
const image_type& img,
const std::string& filename,
int quality = 75
);
/*!
requires
- image_type == an image object that implements the interface defined in
dlib/image_processing/generic_image.h or a matrix expression
- image.size() != 0
ensures
- writes the image to the file indicated by file_name in the JPEG format.
- image[0][0] will be in the upper left corner of the image.
- image[image.nr()-1][image.nc()-1] will be in the lower right corner of the
image.
- This routine can save images containing any type of pixel. However,
save_jpeg() can only natively store rgb_pixel and uint8 pixel types. All
other pixel types will be converted into one of these types as appropriate
before being saved to disk.
throws
- image_save_error
This exception is thrown if there is an error that prevents us from saving
the image.
- std::bad_alloc
!*/
// ----------------------------------------------------------------------------------------
}
#endif // DLIB_SAVE_JPEG_ABSTRACT_Hh_
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