WPoint ImageUtils::getJpegSize(const std::string& fileName)
{
try {
boost::interprocess::file_mapping mapping(fileName.c_str(), boost::interprocess::read_only);
boost::interprocess::mapped_region region(mapping, boost::interprocess::read_only, 0, 2 * 1024 * 1024);
const unsigned char *const header = static_cast<unsigned char*>(region.get_address());
std::size_t headerSize = region.get_size();
std::size_t pos = 2;
if (pos + 12 > headerSize) {
LOG_ERROR("getJpegSize: JPEG file '" <<
fileName << "' is too small, size of mapped region: " <<
headerSize << " bytes");
return WPoint();
}
while (toUnsigned(header[pos])==0xFF) {
if (toUnsigned(header[pos + 1])==0xC0 ||
toUnsigned(header[pos + 1])==0xC1 ||
toUnsigned(header[pos + 1])==0xC2 ||
toUnsigned(header[pos + 1])==0xC3 ||
toUnsigned(header[pos + 1])==0xC9 ||
toUnsigned(header[pos + 1])==0xCA ||
toUnsigned(header[pos + 1])==0xCB)
break;
pos += 2+ (toUnsigned(header[pos + 2])<<8) + toUnsigned(header[pos + 3]);
if (pos + 12 > headerSize) {
LOG_ERROR("getJpegSize: end of mapped region for JPEG file '" <<
fileName << "' reached without finding geometry, size of "
"mapped region: " << headerSize << " bytes");
return WPoint();
}
}
int height = (toUnsigned(header[pos + 5] << 8)) + toUnsigned(header[pos + 6]);
int width = (toUnsigned(header[pos + 7] << 8)) + toUnsigned(header[pos + 8]);
return WPoint(width, height);
} catch (const boost::interprocess::interprocess_exception &e) {
LOG_ERROR("getJpegSize: memory mapping JPEG file '" <<
fileName << "' failed with exception: " << e.what());
return WPoint();
}
}
WPoint ImageUtils::getSize(const std::vector<unsigned char>& header)
{
/*
* Contributed by Daniel Derr @ ArrowHead Electronics Health-Care
*/
std::string mimeType = identifyMimeType(header);
if (mimeType == "image/png") {
int width = ( ( ( toUnsigned(header[16]) << 8
| toUnsigned(header[17])) << 8
| toUnsigned(header[18])) << 8
| toUnsigned(header[19]));
int height = ( ( ( toUnsigned(header[20]) << 8
| toUnsigned(header[21])) << 8
| toUnsigned(header[22])) << 8
| toUnsigned(header[23]));
return WPoint(width, height);
} else if (mimeType == "image/gif") {
int width = toUnsigned(header[7]) << 8 | toUnsigned(header[6]);
int height = toUnsigned(header[9]) << 8 | toUnsigned(header[8]);
return WPoint(width, height);
} else
return WPoint();
}
WPoint ImageUtils::getJpegSize(const std::string& fileName){
std::vector<unsigned char> header =
FileUtils::fileHeader(fileName, 1000);
int pos = 2;
while (toUnsigned(header[pos])==0xFF) {
if (toUnsigned(header[pos + 1])==0xC0 ||
toUnsigned(header[pos + 1])==0xC1 ||
toUnsigned(header[pos + 1])==0xC2 ||
toUnsigned(header[pos + 1])==0xC3 ||
toUnsigned(header[pos + 1])==0xC9 ||
toUnsigned(header[pos + 1])==0xCA ||
toUnsigned(header[pos + 1])==0xCB)
break;
pos += 2+(toUnsigned(header[pos + 2])<<8) + toUnsigned(header[pos + 3]);
if (pos +12 > (int)header.size())
break;
}
int height = (toUnsigned(header[pos + 5] << 8)) + toUnsigned(header[pos + 6]);
int width = (toUnsigned(header[pos + 7] << 8)) + toUnsigned(header[pos + 8]);
return WPoint(width, height);
}
