|| || || || || ||

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ReadImage.h

Go to the documentation of this file.

#ifndef Impala_Core_Array_ReadImage_h
#define Impala_Core_Array_ReadImage_h

#include "Core/Array/Arrays.h"
#include "Core/Array/ReadPng.h"
#include "Core/Array/ReadJpg.h"

namespace Impala
{
namespace Core
{
namespace Array
{


static const int cImageTypeUnknown = 0;
static const int cImageTypeJpg     = 1;
static const int cImageTypePng     = 2;


inline int
ReadImageIdentity(char* buf, int bufSize)
{
    ILOG_VAR(Impala.Core.Array.ReadImageIdentity);
    if (bufSize < 14)
    {
        ILOG_ERROR("Buffer size too small (" << bufSize << ") to identify file");
        return cImageTypeUnknown;
    }

    // PNG image (first 8 bytes are always the same)
    if (((buf[0] == -119) || (buf[0] == 137)) &&  // 0x89 (signed stuff is...)
        (buf[1] == 0x50) &&
        (buf[2] == 0x4e) &&
        (buf[3] == 0x47) &&
        (buf[4] == 0x0d) &&
        (buf[5] == 0x0a) &&
        (buf[6] == 0x1a) &&
        (buf[7] == 0x0a))
    {
        return cImageTypePng;
    }

    // ordinary JFIF JPEG
    if ((buf[0] == -1) &&      // 0xff
        (buf[1] == -40) &&     // 0xd8
        (buf[2] == -1) &&      // 0xff application marker
        //(buf[3] == 0xe0) &&  // application marker
        //                     // (this part can be e0..ef or anything?)
        (buf[6] == 0x4a) &&    // J
        (buf[7] == 0x46) &&    // F
        (buf[8] == 0x49) &&    // I
        (buf[9] == 0x46) &&    // F
        (buf[10] == 0x00))
    {
        return cImageTypeJpg;
    }

    // Exif JPEG ...not tested...
    //is the "Exif" part required to be in this exact location?
    if ((buf[0] == -1) &&       // 0xff
        (buf[1] == -40) &&      // 0xd8
        (buf[2] == -1) &&       // 0xff application marker
        (buf[3] == -31) &&      // 0xe1 application marker
                                // (this part has to be e1 for exif)
        (buf[8] == 0x45) &&     // E
        (buf[9] == 0x78) &&     // x
        (buf[10] == 0x69) &&    // i
        (buf[11] == 0x66) &&    // f
        (buf[12] == 0x00) &&    // \0
        (buf[13] == 0x00))      // \0
    {
        return cImageTypeJpg;
    }
    // Exif JPEG 2nd form: Exif 2 bytes back
    //is the "Exif" part required to be in this exact location?
    if ((buf[0] == -1) &&       // 0xff
        (buf[1] == -40) &&      // 0xd8
        (buf[2] == -1) &&       // 0xff application marker
        (buf[3] == -31) &&      // 0xe1 application marker
                                // (this part has to be e1 for exif)
        (buf[6] == 0x45) &&     // E
        (buf[7] == 0x78) &&     // x
        (buf[8] == 0x69) &&     // i
        (buf[9] == 0x66) &&     // f
        (buf[10] == 0x00) &&    // \0
        (buf[11] == 0x00))      // \0
    {
        return cImageTypeJpg;
    }


    // Only these 3 bytes seem to be enough for JPEG?
    if ((buf[0] == -1) &&       // 0xff
        (buf[1] == -40) &&      // 0xd8
        (buf[2] == -1))       // 0xff application marker
    {
        return cImageTypeJpg;
    }


    ILOG_ERROR("Unknown image file format! 0:" << int(buf[0]) << " 1:" <<
               int(buf[1]) << " 2:" << int(buf[2]) << " 3:" << int(buf[3]) <<
               " 4:" << int(buf[4]) << " 5:" << int(buf[5]) << " 6:" <<
               int(buf[6]) << " 7:" << int(buf[7]) << " 8:" << int(buf[8]) <<
               " 9:" << int(buf[9]) << " 10:" << int(buf[10]) << " 11:" <<
               int(buf[11]) << " 12:" << int(buf[12]) << " 13:" << int(buf[13]));

    std::ostringstream oss;
    oss << "header:" << std::endl;
    for (int i=0 ; i<14 ; i++)
    {
        oss << "header[" << std::dec << i << "] = " << std::hex << "0x"
            << UInt8(buf[i]) << " = " << std::dec << int(buf[i]) << " = "
            << buf[i] << std::endl;
    }
    ILOG_INFO(oss.str());

    return cImageTypeUnknown;
}
template <class ArrayT>
inline void
ReadImageFromMemory(ArrayT*& dst, char* buf, int bufSize)
{
    ILOG_VAR(Impala.Core.Array.ReadImageFromMemory);
    int imType = ReadImageIdentity(buf, bufSize);

    if (imType == cImageTypePng)
    {
        ReadPngFromMemory(dst, buf, bufSize);
        return;
    }
    if (imType == cImageTypeJpg)
    {
        ReadJpgFromMemory(dst, buf, bufSize);
        return;
    }
}

template <class ArrayT>
inline void
ReadImage(ArrayT*& dst, Persistency::File file)
{
    ILOG_VAR(Impala.Core.Array.ReadImage);
    Util::IOBuffer* ioBuf = file.GetReadBuffer();
    if (!ioBuf)
        return;

    size_t bufSize = ioBuf->Size();
    char* buf = new char[bufSize];
    size_t nrRead = ioBuf->Read(buf, bufSize);
    if (nrRead != bufSize)
    {
        ILOG_ERROR("Buffer read failed");
        delete buf;
        delete ioBuf;
        return;
    }

    int imType = ReadImageIdentity(buf, bufSize);
    String nameExt = FileNameExt(file.GetPath(), true);
    if (imType == cImageTypePng)
    {
        if ((nameExt == "jpg") || (nameExt == "jpeg"))
            ILOG_WARN("File seems to contain a PNG instead of a JPG image");
        ReadPngFromMemory(dst, buf, bufSize);
    }
    else if (imType == cImageTypeJpg)
    {
        if (nameExt == "png")
            ILOG_WARN("File seems to contain a JPG instead of a PNG image");
        ReadJpgFromMemory(dst, buf, bufSize);
    }
    else
    {
        ILOG_ERROR("Don't understand " << file.GetPath());
    }

    delete buf;
    delete ioBuf;
}

} // namespace Array
} // namespace Core
} // namespace Impala

#endif

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