EerFrame.cpp

// Copyright (c) 2019 by FEI Company

#include "EerFrame.h"
#include <string>
#include <stdexcept>

namespace Fei {
namespace Acquisition {
namespace EerReader {

namespace {
    const uint16_t TIFF_COMPRESSION_EER_V0 = 65000;
    const uint16_t TIFF_COMPRESSION_EER_V1 = 65001;
    const uint16_t TIFF_COMPRESSION_EER_V2 = 65002;


    const uint16_t EER_DECODER_SKIPBITS = 65007;
    const uint16_t EER_DECODER_HORZBITS = 65008;
    const uint16_t EER_DECODER_VERTBITS = 65009;
}

EerFrame::EerFrame(TIFF * tiff)
{
    TIFFGetField(tiff, TIFFTAG_IMAGEWIDTH, &m_imageWidth);
    TIFFGetField(tiff, TIFFTAG_IMAGELENGTH, &m_imageLength);
    auto compression = uint16_t(0);
    TIFFGetField(tiff, TIFFTAG_COMPRESSION, &compression);
    if (compression == TIFF_COMPRESSION_EER_V2)
    {
        m_encodingVersion = 2;
        TIFFGetField(tiff, EER_DECODER_SKIPBITS, &m_rleBits);
        TIFFGetField(tiff, EER_DECODER_HORZBITS, &m_horzSubBits);
        TIFFGetField(tiff, EER_DECODER_VERTBITS, &m_vertSubBits);
    }
    else if (compression == TIFF_COMPRESSION_EER_V1)
    {
        m_encodingVersion = 1;
        m_rleBits = 7;
        m_horzSubBits = 2;
        m_vertSubBits = 2;
    }
    else if (compression == TIFF_COMPRESSION_EER_V0)
    {
        m_encodingVersion = 0;
        m_rleBits = 8;
        m_horzSubBits = 2;
        m_vertSubBits = 2;
    }
    else
        throw std::runtime_error("EerFrame: Unknown compression encoding " + std::to_string(compression));

    auto nrOfStrips = TIFFNumberOfStrips(tiff);
    for (uint32_t i = 0; i < nrOfStrips; i++)
    {
        auto previousSize = m_eerData.size();
        auto stripSize = TIFFRawStripSize(tiff, i);
        m_eerData.resize(previousSize + stripSize);

        TIFFReadRawStrip(tiff, i, m_eerData.data() + previousSize, stripSize);
    }
}

uint32_t EerFrame::GetWidth() const
{
    return m_imageWidth;
}

uint32_t EerFrame::GetLength() const
{
    return m_imageLength;
}

uint16_t EerFrame::GetRleBits() const
{
    return m_rleBits;
}

uint16_t EerFrame::GetHorzSubBits() const
{
    return m_horzSubBits;
}

uint16_t EerFrame::GetVertSubBits() const
{
    return m_vertSubBits;
}

std::vector<unsigned char> EerFrame::GetEerData() const
{
    return m_eerData;
}

int EerFrame::GetEncodingVersion() const
{
    return m_encodingVersion;
}

} //namespace EerReader
} //namespace Acquisition
} //namespace Fei