pnmCodec.hpp

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// Copyright (c) 2011 Michael D. Adams
// All rights reserved.

// __START_OF_LICENSE__
// 
// Copyright (c) 2015 Michael D. Adams
// All rights reserved.
// 
// This file is part of the Signal Processing Library (SPL).
// 
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 3,
// or (at your option) any later version.
// 
// This program 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 for more details.
// 
// You should have received a copy of the GNU General Public
// License along with this program; see the file LICENSE.  If not,
// see <http://www.gnu.org/licenses/>.
// 
// __END_OF_LICENSE__

#ifndef SPL_pnmCodec_hpp
#define SPL_pnmCodec_hpp

//

#include <SPL/config.hpp>
#include <iostream>
#include <sstream>
#include <cassert>
#include <cstdlib>

//

namespace SPL {

//

enum PnmMagic {
        pnmMagicInvalid = 0,
        pnmMagicTxtPbm = 0x5031,
        pnmMagicTxtPgm = 0x5032,
        pnmMagicTxtPpm = 0x5033,
        pnmMagicBinPbm = 0x5034,
        pnmMagicBinPgm = 0x5035,
        pnmMagicBinPpm = 0x5036,
        pnmMagicPam = 0x5037
};

enum PnmType {
        pnmTypeInvalid = 0,
        pnmTypePbm,
        pnmTypePgm,
        pnmTypePpm
};

enum PnmFmt {
        pnmFmtInvalid = 0,
        pnmFmtTxt,
        pnmFmtBin
};

const int pnmMaxLineLen = 80;

struct PnmHeader
{
        PnmMagic magic;

        int width;

        int height;

        int maxVal;

        bool sgnd;
};

PnmType pnmGetType(PnmMagic magic);

PnmFmt pnmGetFmt(PnmMagic magic);

int pnmMaxValToPrec(int maxVal);

int pnmGetNumComps(PnmType type);

inline long pnmOnes(int n)
{
        return (1UL << n) - 1;
}

//

int pnmGetHeader(std::istream& in, PnmHeader& header);

int pnmPutHeader(std::ostream& out, PnmHeader& header);

int pnmGetChar(std::istream& in);

int pnmGetTxtBit(std::istream& in);

long pnmGetTxtInt(std::istream& in, bool sgnd, int& status);

long pnmGetBinInt(std::istream& in, int wordSize, bool sgnd, int& status);

int pnmPutBinInt(std::ostream& out, int wordSize, bool sgnd, long val);

// Encoder

template <class GetData>
int pnmEncode(std::ostream& outStream, int width, int height, int numComps,
  int maxVal, bool sgnd, GetData& getData, bool binaryFormat)
{
        PnmHeader header;
        if (numComps == 1) {
                if (maxVal == 1) {
                        header.magic = binaryFormat ? pnmMagicBinPbm : pnmMagicTxtPbm;
                } else {
                        header.magic = binaryFormat ? pnmMagicBinPgm : pnmMagicTxtPgm;
                }
        } else if (numComps == 3) {
                header.magic = binaryFormat ? pnmMagicBinPpm : pnmMagicTxtPpm;
        } else {
                return -1;
        }
        header.width = width;
        header.height = height;
        header.maxVal = maxVal;
        header.sgnd = false;

        if (pnmPutHeader(outStream, header)) {
                return -1;
        }
        if (putData(outStream, header, getData)) {
                return -1;
        }
        return 0;
}

template <class GetData>
int putData(std::ostream& out, PnmHeader& header, GetData& getData)
{
        int prec = pnmMaxValToPrec(header.maxVal);
        int fmt = pnmGetFmt(header.magic);
        PnmType type = pnmGetType(header.magic);
        int numComps = pnmGetNumComps(type);

        int lineLen = 0;
        for (int y = header.height - 1; y >= 0; --y) {
                if (fmt == pnmFmtBin) {
                        if (type == pnmTypePbm) {
                                int val = 0;
                                int numBits = 0;
                                for (int x = 0; x < header.width; ++x) {
                                        long b = getData();
                                        val = (val << 1) | (b & 1);
                                        ++numBits;
                                        if (numBits >= 8) {
                                                if (!out.put(static_cast<unsigned char>(val))) {
                                                        return -1;
                                                }
                                                val = 0;
                                                numBits = 0;
                                        }
                                }
                                if (numBits > 0) {
                                        assert(numBits <= 8);
                                        val <<= 8 - numBits;
                                        if (!out.put(static_cast<unsigned char>(val))) {
                                                return -1;
                                        }
                                }
                        } else {
                                for (int x = 0; x < header.width; ++x) {
                                        for (int c = 0; c < numComps; ++c) {
                                                //long val = img.get(c, x, y);
                                                long val = getData();
                                                if (pnmPutBinInt(out, prec, header.sgnd, val)) {
                                                        return -1;
                                                }
                                        }
                                }
                        }
                } else {
                        for (int x = 0; x < header.width; ++x) {
                                for (int c = 0; c < numComps; ++c) {
                                        //long val = img.get(c, x, y);
                                        long val = getData();
                                        std::ostringstream buf;
                                        buf << val;
                                        int n = buf.str().length();
                                        if (lineLen && lineLen + n + 2 > pnmMaxLineLen) {
                                                out << "\n";
                                                lineLen = 0;
                                        }
                                        if (lineLen && prec > 1) {
                                                out << " ";
                                                ++lineLen;
                                        }
                                        out << buf.str();
                                        lineLen += n;
                                }
                        }
                }
                if (fmt == pnmFmtTxt && lineLen) {
                        out << "\n";
                        lineLen = 0;
                }
        }

        return 0;
}

// Decoder

template <class Initialize>
int pnmDecode(std::istream& inStream, Initialize& initialize)
{
        PnmHeader header;
        if (pnmGetHeader(inStream, header)) {
                return -1;
        }
#if defined(PNM_DEBUG)
        std::cerr
          << "magic " << std::hex << header.magic << " "
          << std::dec << " width " << header.width << " "
          << "height " << header.height << " "
          << "maxVal " << header.maxVal << "\n"
          ;
#endif
        int numComps = pnmGetNumComps(pnmGetType(header.magic));
        typename Initialize::PutData putData;
        initialize(header.width, header.height, numComps, header.maxVal, header.sgnd, putData);
        if (getData(inStream, header, putData)) {
                return -1;
        }
        return 0;
}

template <class PutData>
int getData(std::istream& in, PnmHeader& header, PutData& putData)
{
        PnmType type = pnmGetType(header.magic);
        PnmFmt fmt = pnmGetFmt(header.magic);
        int numComps = pnmGetNumComps(type);
        int prec = pnmMaxValToPrec(header.maxVal);
        for (int y = header.height - 1; y >= 0; --y) {
                if (type == pnmTypePbm) {
                        if (fmt == pnmFmtBin) {
                                for (int x = 0; x < header.width;) {
                                        int c;
                                        if ((c = in.get()) == std::char_traits<char>::eof()) {
                                                return -1;
                                        }
                                        int n = 8;
                                        while (n > 0 && x < header.width) {
                                                //img.set(0, x, y, (c >> 7) & 1);
                                                putData((c >> 7) & 1);
                                                c <<= 1;
                                                --n;
                                                ++x;
                                        }
                                }
                        } else {
                                for (int x = 0; x < header.width; ++x) {
                                        long val;
                                        if ((val = pnmGetTxtBit(in)) < 0) {
                                                return -1;
                                        }
                                        //img.set(0, x, y, val);
                                        putData(val);
                                }
                        }
                } else {
                        if (fmt == pnmFmtBin) {
                                for (int x = 0; x < header.width; ++x) {
                                        for (int c = 0; c < numComps; ++c) {
                                                long val;
                                                int status;
                                                if (val = pnmGetBinInt(in, prec, header.sgnd, status),
                                                  status) {
                                                        return -1;
                                                }
                                                //img.set(c, x, y, val);
                                                putData(val);
                                        }
                                }
                        } else {
                                for (int x = 0; x < header.width; ++x) {
                                        for (int c = 0; c < numComps; ++c) {
                                                long val;
                                                int status;
                                                if (val = pnmGetTxtInt(in, header.sgnd, status), status) {
                                                        return -1;
                                                }
                                                //img.set(c, x, y, val);
                                                putData(val);
                                        }
                                }
                        }
                }
        }
        return 0;
}

//

}

#endif