CImage_JPEG_streams.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2018, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */
 
#include "img-precomp.h"  // Precompiled headers
 
#include <mrpt/img/CImage.h>
#include <mrpt/io/CStream.h>
 
// Universal include for all versions of OpenCV
#include <mrpt/otherlibs/do_opencv_includes.h>
 
using namespace mrpt;
using namespace mrpt::img;
 
// ---------------------------------------------------------------------------------------
//                                                      START OF JPEG FUNCTIONS PART
// ---------------------------------------------------------------------------------------
/* Expanded data destination object for stdio output */
 
//#undef INT32
#undef FAR
#define XMD_H
 
#include <stdio.h>
 
#include <jpeglib.h>
#define mrpt_jpeg_source_mgr jpeg_source_mgr
 
using mrpt::io::CStream;
 
typedef struct
{
        struct jpeg_destination_mgr pub; /* public fields */
 
        CStream* out; /* target stream */
        JOCTET* buffer; /* start of buffer */
} mrpt_destination_mgr;
 
using mrpt_dest_ptr = mrpt_destination_mgr*;
 
#define OUTPUT_BUF_SIZE 4096 /* choose an efficiently fwrite'able size */
 
/*
 * Initialize destination --- called by jpeg_start_compress
 * before any data is actually written.
 */
 
METHODDEF(void)
init_destination(j_compress_ptr cinfo)
{
        mrpt_dest_ptr dest = (mrpt_dest_ptr)cinfo->dest;
 
        /* Allocate the output buffer --- it will be released when done with image
         */
        dest->buffer = (JOCTET*)(*cinfo->mem->alloc_small)(
                (j_common_ptr)cinfo, JPOOL_IMAGE, OUTPUT_BUF_SIZE * sizeof(JOCTET));
 
        dest->pub.next_output_byte = dest->buffer;
        dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
}
 
/*
 * Empty the output buffer --- called whenever buffer fills up.
 *
 * In typical applications, this should write the entire output buffer
 * (ignoring the current state of next_output_byte & free_in_buffer),
 * reset the pointer & count to the start of the buffer, and return TRUE
 * indicating that the buffer has been dumped.
 *
 * In applications that need to be able to suspend compression due to output
 * overrun, a FALSE return indicates that the buffer cannot be emptied now.
 * In this situation, the compressor will return to its caller (possibly with
 * an indication that it has not accepted all the supplied scanlines).  The
 * application should resume compression after it has made more room in the
 * output buffer.  Note that there are substantial restrictions on the use of
 * suspension --- see the documentation.
 *
 * When suspending, the compressor will back up to a convenient restart point
 * (typically the start of the current MCU). next_output_byte & free_in_buffer
 * indicate where the restart point will be if the current call returns FALSE.
 * Data beyond this point will be regenerated after resumption, so do not
 * write it out when emptying the buffer externally.
 */
 
METHODDEF(boolean)
empty_output_buffer(j_compress_ptr cinfo)
{
        mrpt_dest_ptr dest = (mrpt_dest_ptr)cinfo->dest;
 
        dest->out->Write(dest->buffer, OUTPUT_BUF_SIZE);
 
        dest->pub.next_output_byte = dest->buffer;
        dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
 
        return TRUE;
}
 
/*
 * Terminate destination --- called by jpeg_finish_compress
 * after all data has been written.  Usually needs to flush buffer.
 *
 * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
 * application must deal with any cleanup that should happen even
 * for error exit.
 */
 
METHODDEF(void)
term_destination(j_compress_ptr cinfo)
{
        mrpt_dest_ptr dest = (mrpt_dest_ptr)cinfo->dest;
        size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
 
        /* Write any data remaining in the buffer */
        if (datacount > 0) dest->out->Write(dest->buffer, (int)datacount);
}
 
GLOBAL(void)
jpeg_stdio_dest(j_compress_ptr cinfo, CStream* out)
{
        mrpt_dest_ptr dest;
 
        /* The destination object is made permanent so that multiple JPEG images
         * can be written to the same file without re-executing jpeg_stdio_dest.
         * This makes it dangerous to use this manager and a different destination
         * manager serially with the same JPEG object, because their private object
         * sizes may be different.  Caveat programmer.
         */
        if (cinfo->dest == nullptr)
        { /* first time for this JPEG object? */
                cinfo->dest = (jpeg_destination_mgr*)(*cinfo->mem->alloc_small)(
                        (j_common_ptr)cinfo, JPOOL_PERMANENT, sizeof(mrpt_destination_mgr));
        }
 
        dest = (mrpt_dest_ptr)cinfo->dest;
        dest->pub.init_destination = init_destination;
        dest->pub.empty_output_buffer = empty_output_buffer;
        dest->pub.term_destination = term_destination;
        dest->out = out;
}
 
// -------------------------------------------------------------
 
/* Expanded data source object for stdio input */
 
typedef struct
{
        mrpt_jpeg_source_mgr pub; /* public fields */
        CStream* in; /* source stream */
        JOCTET* buffer; /* start of buffer */
        boolean start_of_file; /* have we gotten any data yet? */
} my_source_mgr;
 
using my_src_ptr = my_source_mgr*;
 
#define INPUT_BUF_SIZE 4096 /* choose an efficiently fread'able size */
 
/*
 * Initialize source --- called by jpeg_read_header
 * before any data is actually read.
 */
 
METHODDEF(void)
init_source(j_decompress_ptr cinfo)
{
        my_src_ptr src = (my_src_ptr)cinfo->src;
 
        /* We reset the empty-input-file flag for each image,
         * but we don't clear the input buffer.
         * This is correct behavior for reading a series of images from one source.
         */
        src->start_of_file = TRUE;
}
 
/*
 * Fill the input buffer --- called whenever buffer is emptied.
 *
 * In typical applications, this should read fresh data into the buffer
 * (ignoring the current state of next_input_byte & bytes_in_buffer),
 * reset the pointer & count to the start of the buffer, and return TRUE
 * indicating that the buffer has been reloaded.  It is not necessary to
 * fill the buffer entirely, only to obtain at least one more byte.
 *
 * There is no such thing as an EOF return.  If the end of the file has been
 * reached, the routine has a choice of ERREXIT() or inserting fake data into
 * the buffer.  In most cases, generating a warning message and inserting a
 * fake EOI marker is the best course of action --- this will allow the
 * decompressor to output however much of the image is there.  However,
 * the resulting error message is misleading if the real problem is an empty
 * input file, so we handle that case specially.
 *
 * In applications that need to be able to suspend compression due to input
 * not being available yet, a FALSE return indicates that no more data can be
 * obtained right now, but more may be forthcoming later.  In this situation,
 * the decompressor will return to its caller (with an indication of the
 * number of scanlines it has read, if any).  The application should resume
 * decompression after it has loaded more data into the input buffer.  Note
 * that there are substantial restrictions on the use of suspension --- see
 * the documentation.
 *
 * When suspending, the decompressor will back up to a convenient restart point
 * (typically the start of the current MCU). next_input_byte & bytes_in_buffer
 * indicate where the restart point will be if the current call returns FALSE.
 * Data beyond this point must be rescanned after resumption, so move it to
 * the front of the buffer rather than discarding it.
 */
 
METHODDEF(boolean)
fill_input_buffer(j_decompress_ptr cinfo)
{
        my_src_ptr src = (my_src_ptr)cinfo->src;
        size_t nbytes;
 
        nbytes = src->in->Read(src->buffer, INPUT_BUF_SIZE);
 
        if (nbytes <= 0)
        {
                if (src->start_of_file) /* Treat empty input file as fatal error */
                {
                        THROW_EXCEPTION("Error looking for JPEG start data!");
                }
 
                /* Insert a fake EOI marker */
                src->buffer[0] = (JOCTET)0xFF;
                src->buffer[1] = (JOCTET)JPEG_EOI;
                nbytes = 2;
        }
 
        src->pub.next_input_byte = src->buffer;
        src->pub.bytes_in_buffer = nbytes;
        src->start_of_file = FALSE;
 
        return TRUE;
}
 
/*
 * Skip data --- used to skip over a potentially large amount of
 * uninteresting data (such as an APPn marker).
 *
 * Writers of suspendable-input applications must note that skip_input_data
 * is not granted the right to give a suspension return.  If the skip extends
 * beyond the data currently in the buffer, the buffer can be marked empty so
 * that the next read will cause a fill_input_buffer call that can suspend.
 * Arranging for additional bytes to be discarded before reloading the input
 * buffer is the application writer's problem.
 */
 
METHODDEF(void)
skip_input_data(j_decompress_ptr cinfo, long num_bytes)
{
        my_src_ptr src = (my_src_ptr)cinfo->src;
 
        /* Just a dumb implementation for now.  Could use fseek() except
         * it doesn't work on pipes.  Not clear that being smart is worth
         * any trouble anyway --- large skips are infrequent.
         */
        if (num_bytes > 0)
        {
                while (num_bytes > (long)src->pub.bytes_in_buffer)
                {
                        num_bytes -= (long)src->pub.bytes_in_buffer;
                        (void)fill_input_buffer(cinfo);
                        /* note we assume that fill_input_buffer will never return FALSE,
                         * so suspension need not be handled.
                         */
                }
                src->pub.next_input_byte += (size_t)num_bytes;
                src->pub.bytes_in_buffer -= (size_t)num_bytes;
        }
}
 
/*
 * An additional method that can be provided by data source modules is the
 * resync_to_restart method for error recovery in the presence of RST markers.
 * For the moment, this source module just uses the default resync method
 * provided by the JPEG library.  That method assumes that no backtracking
 * is possible.
 */
 
/*
 * Terminate source --- called by jpeg_finish_decompress
 * after all data has been read.  Often a no-op.
 *
 * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
 * application must deal with any cleanup that should happen even
 * for error exit.
 */
 
METHODDEF(void)
term_source(j_decompress_ptr cinfo)
{
        MRPT_UNUSED_PARAM(cinfo);
        /* no work necessary here */
}
 
/*
 * Prepare for input from a stdio stream.
 * The caller must have already opened the stream, and is responsible
 * for closing it after finishing decompression.
 */
 
GLOBAL(void)
jpeg_stdio_src(j_decompress_ptr cinfo, CStream* in)
{
        my_src_ptr src;
 
        /* The source object and input buffer are made permanent so that a series
         * of JPEG images can be read from the same file by calling jpeg_stdio_src
         * only before the first one.  (If we discarded the buffer at the end of
         * one image, we'd likely lose the start of the next one.)
         * This makes it unsafe to use this manager and a different source
         * manager serially with the same JPEG object.  Caveat programmer.
         */
        if (cinfo->src == nullptr)
        { /* first time for this JPEG object? */
                cinfo->src = (mrpt_jpeg_source_mgr*)(*cinfo->mem->alloc_small)(
                        (j_common_ptr)cinfo, JPOOL_PERMANENT, sizeof(my_source_mgr));
                src = (my_src_ptr)cinfo->src;
                src->buffer = (JOCTET*)(*cinfo->mem->alloc_small)(
                        (j_common_ptr)cinfo, JPOOL_PERMANENT,
                        INPUT_BUF_SIZE * sizeof(JOCTET));
        }
 
        src = (my_src_ptr)cinfo->src;
        src->pub.init_source = init_source;
        src->pub.fill_input_buffer = fill_input_buffer;
        src->pub.skip_input_data = skip_input_data;
        src->pub.resync_to_restart =
                jpeg_resync_to_restart; /* use default method */
        src->pub.term_source = term_source;
        src->in = in;
        src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
        src->pub.next_input_byte = nullptr; /* until buffer loaded */
}
 
// ---------------------------------------------------------------------------------------
//                                                      END OF JPEG FUNCTIONS PART
// ---------------------------------------------------------------------------------------
 
/*---------------------------------------------------------------
                                        saveToStreamAsJPEG
 ---------------------------------------------------------------*/
void CImage::saveToStreamAsJPEG(CStream& out, const int jpeg_quality) const
{
#if MRPT_HAS_OPENCV
        MRPT_START
 
        makeSureImageIsLoaded();  // For delayed loaded images stored externally
 
        struct jpeg_compress_struct cinfo;
        struct jpeg_error_mgr jerr;
 
        const IplImage* ipl = static_cast<const IplImage*>(img);
 
        const unsigned int nCols = ipl->width;
        const unsigned int nRows = ipl->height;
        const bool is_color = (ipl->nChannels == 3);
 
        // Some previous verification:
        ASSERT_(nCols >= 1 && nRows >= 1);
        ASSERT_(ipl);
        ASSERT_(ipl->nChannels == 1 || ipl->nChannels == 3);
 
        // 1) Initialization of the JPEG compresion object:
        // --------------------------------------------------
        cinfo.err = jpeg_std_error(&jerr);
        jpeg_create_compress(&cinfo);
 
        // 2) Set the destination of jpeg data:
        // --------------------------------------------------
        jpeg_stdio_dest(&cinfo, &out);
 
        // 3) Set parameters for compression:
        // --------------------------------------------------
        cinfo.image_width = nCols;
        cinfo.image_height = nRows;
        cinfo.input_components = is_color ? 3 : 1;
        cinfo.in_color_space = is_color ? JCS_RGB : JCS_GRAYSCALE;
 
        jpeg_set_defaults(&cinfo);
        /* Make optional parameter settings here */
        /* Now you can set any non-default parameters you wish to.
         * Here we just illustrate the use of quality (quantization table) scaling:
         */
        jpeg_set_quality(
                &cinfo, jpeg_quality /* quality per cent */,
                TRUE /* limit to baseline-JPEG values */);
 
        // 4) Start:
        // --------------------------------------------------
        jpeg_start_compress(&cinfo, TRUE);
 
        // 5) Write scan lines:
        // --------------------------------------------------
        if (is_color)
        {
                JSAMPROW row_pointer[1]; /* pointer to a single row */
                row_pointer[0] = (JSAMPROW) new char[ipl->widthStep];
 
                for (unsigned int row = 0; row < nRows; row++)
                {
                        // Flip RGB bytes order!
                        char* src;
                        if (ipl->origin == 0)
                                src = &ipl->imageData[row * ipl->widthStep];
                        else
                                src = &ipl->imageData[(nRows - 1 - row) * ipl->widthStep];
                        char* target = (char*)row_pointer[0];
                        for (unsigned int col = 0; col < nCols; col++)
                        {
                                target[0] = src[2];
                                target[1] = src[1];
                                target[2] = src[0];
 
                                target += 3;
                                src += 3;
                        }
 
                        if (1 != jpeg_write_scanlines(&cinfo, row_pointer, 1))
                        {
                                THROW_EXCEPTION("jpeg_write_scanlines: didn't work!!");
                        }
                }
 
                delete[] row_pointer[0];
        }  // end "color"
        else
        {  // Is grayscale:
                JSAMPROW row_pointer[1]; /* pointer to a single row */
 
                for (unsigned int row = 0; row < nRows; row++)
                {
                        if (ipl->origin == 0)
                                row_pointer[0] =
                                        (JSAMPROW)&ipl->imageData[row * ipl->widthStep];
                        else
                                row_pointer[0] =
                                        (JSAMPROW)&ipl
                                                ->imageData[(nRows - 1 - row) * ipl->widthStep];
 
                        // Gray scale:
                        if (1 != jpeg_write_scanlines(&cinfo, row_pointer, 1))
                        {
                                THROW_EXCEPTION("jpeg_write_scanlines: didn't work!!");
                        }
                }
        }
 
        // 6) Compress and finish:
        // --------------------------------------------------
        jpeg_finish_compress(&cinfo);
        jpeg_destroy_compress(&cinfo);
 
        // DONE!
        MRPT_END
#endif
}
 
/*---------------------------------------------------------------
                                        saveToStreamAsJPEG
 ---------------------------------------------------------------*/
void CImage::loadFromStreamAsJPEG(CStream& in)
{
#if MRPT_HAS_OPENCV
        MRPT_START
 
        struct jpeg_decompress_struct cinfo;
        struct jpeg_error_mgr jerr;
 
        /* Step 1: allocate and initialize JPEG decompression object */
 
        /* We set up the normal JPEG error routines, then override error_exit. */
        cinfo.err = jpeg_std_error(&jerr);
 
        /* Now we can initialize the JPEG decompression object. */
        jpeg_create_decompress(&cinfo);
 
        /* Step 2: specify data source (eg, a file) */
        jpeg_stdio_src(&cinfo, &in);
 
        /* Step 3: read file parameters with jpeg_read_header() */
        jpeg_read_header(&cinfo, TRUE);
 
        /* Step 4: set parameters for decompression */
 
        /* Step 5: Start decompressor */
        jpeg_start_decompress(&cinfo);
 
        /* We may need to do some setup of our own at this point before reading
         * the data.  After jpeg_start_decompress() we have the correct scaled
         * output image dimensions available, as well as the output colormap
         * if we asked for color quantization.
         * In this example, we need to make an output work buffer of the right size.
         */
        /* JSAMPLEs per row in output buffer */
        /* physical row width in output buffer */
        const int row_stride = cinfo.output_width * cinfo.output_components;
        /* Make a one-row-high sample array that will go away when done with image
         */
        /* Output row buffer */
        JSAMPARRAY buffer = (*cinfo.mem->alloc_sarray)(
                (j_common_ptr)&cinfo, JPOOL_IMAGE, row_stride, 1);
 
        // Resize the CImage now:
        this->changeSize(
                cinfo.output_width, cinfo.output_height, cinfo.out_color_components,
                true);
        IplImage* ipl = static_cast<IplImage*>(img);
 
        /* Step 6: while (scan lines remain to be read) */
        /*           jpeg_read_scanlines(...); */
 
        /* Here we use the library's state variable cinfo.output_scanline as the
         * loop counter, so that we don't have to keep track ourselves.
         */
        const unsigned int nCols = cinfo.output_width;
        const unsigned int nRows = cinfo.output_height;
 
        for (unsigned int row = 0; row < nRows; row++)
        {
                /* jpeg_read_scanlines expects an array of pointers to scanlines.
                 * Here the array is only one element long, but you could ask for
                 * more than one scanline at a time if that's more convenient.
                 */
                jpeg_read_scanlines(&cinfo, buffer, 1);
 
                /* Copy into the CImage object */
                if (isColor())
                {
                        // Flip RGB bytes order!
                        char* target = &ipl->imageData[row * ipl->widthStep];
                        const char* src = (char*)buffer[0];
                        for (unsigned int col = 0; col < nCols; col++)
                        {
                                target[0] = src[2];
                                target[1] = src[1];
                                target[2] = src[0];
 
                                target += 3;
                                src += 3;
                        }
                }
                else
                {
                        // Gray scale:
                        memcpy(
                                &ipl->imageData[row * ipl->widthStep], buffer[0], row_stride);
                }
        }
 
        /* Step 7: Finish decompression */
 
        jpeg_finish_decompress(&cinfo);
        /* We can ignore the return value since suspension is not possible
         * with the stdio data source.
         */
 
        /* Step 8: Release JPEG decompression object */
 
        /* This is an important step since it will release a good deal of memory. */
        jpeg_destroy_decompress(&cinfo);
 
        // DONE!
        MRPT_END
#endif
}