/*--------------------------------------------------------------------------
Process a EXIF marker
Describes all the drivel that most digital cameras include...
--------------------------------------------------------------------------*/
bool Cexif::process_EXIF(unsigned char * CharBuf, unsigned int length)
{
m_exifinfo->FlashUsed = 0;
/* If it's from a digicam, and it used flash, it says so. */
m_exifinfo->Comments[0] = '\0'; /* Initial value - null string */
ExifImageWidth = 0;
{ /* Check the EXIF header component */
static const unsigned char ExifHeader[] = "Exif\0\0";
if (memcmp(CharBuf+0, ExifHeader,6)){
strcpy(m_szLastError,"Incorrect Exif header");
return 0;
}
}
if (memcmp(CharBuf+6,"II",2) == 0){
MotorolaOrder = 0;
}else{
if (memcmp(CharBuf+6,"MM",2) == 0){
MotorolaOrder = 1;
}else{
strcpy(m_szLastError,"Invalid Exif alignment marker.");
return 0;
}
}
/* Check the next two values for correctness. */
if (Get16u(CharBuf+8) != 0x2a){
strcpy(m_szLastError,"Invalid Exif start (1)");
return 0;
}
int FirstOffset = Get32u(CharBuf+10);
if (FirstOffset < 8 || FirstOffset > 16){
// I used to ensure this was set to 8 (website I used indicated its 8)
// but PENTAX Optio 230 has it set differently, and uses it as offset. (Sept 11 2002)
strcpy(m_szLastError,"Suspicious offset of first IFD value");
return 0;
}
unsigned char * LastExifRefd = CharBuf;
/* First directory starts 16 unsigned chars in. Offsets start at 8 unsigned chars in. */
if (!ProcessExifDir(CharBuf+14, CharBuf+6, length-6, m_exifinfo, &LastExifRefd))
return 0;
/* This is how far the interesting (non thumbnail) part of the exif went. */
// int ExifSettingsLength = LastExifRefd - CharBuf;
/* Compute the CCD width, in milimeters. */
if (m_exifinfo->FocalplaneXRes != 0){
m_exifinfo->CCDWidth = (float)(ExifImageWidth * m_exifinfo->FocalplaneUnits / m_exifinfo->FocalplaneXRes);
}
return 1;
}
/*--------------------------------------------------------------------------
Process a EXIF marker
Describes all the drivel that most digital cameras include...
--------------------------------------------------------------------------*/
bool CxImageJPG::CxExifInfo::exif_process(unsigned char * CharBuf, unsigned int length, EXIFINFO* pInfo)
{
int ExifSettingsLength;
unsigned char * LastExifRefd;
pInfo->FlashUsed = 0;
/* If it's from a digicam, and it used flash, it says so. */
pInfo->Comments[0] = '\0'; /* Initial value - null string */
FocalplaneXRes = 0;
FocalplaneUnits = 0;
ExifImageWidth = 0;
{ /* Check the EXIF header component */
static const unsigned char ExifHeader[] = "Exif\0\0";
if (memcmp(CharBuf+0, ExifHeader,6)){
strcpy(m_szLastError,"Incorrect Exif header");
return false;
}
}
if (memcmp(CharBuf+6,"II",2) == 0){
MotorolaOrder = 0;
}else{
if (memcmp(CharBuf+6,"MM",2) == 0){
MotorolaOrder = 1;
}else{
strcpy(m_szLastError,"Invalid Exif alignment marker.");
return false;
}
}
/* Check the next two values for correctness. */
if (Get16u(CharBuf+8) != 0x2a || Get32u(CharBuf+10) != 0x08){
strcpy(m_szLastError,"Invalid Exif start (1)");
return false;
}
LastExifRefd = CharBuf;
/* First directory starts 16 bytes in. Offsets start at 8 bytes in. */
if (!ProcessExifDir(CharBuf+14, CharBuf+6, length-6, pInfo, &LastExifRefd))
return false;
/* This is how far the interesting (non thumbnail) part of the exif went.
*/
ExifSettingsLength = LastExifRefd - CharBuf;
/* Compute the CCD width, in milimeters. */
if (FocalplaneXRes != 0){
pInfo->CCDWidth =
(float)(ExifImageWidth * FocalplaneUnits / FocalplaneXRes);
}
return true;
}
//--------------------------------------------------------------------------
// Process a EXIF marker
// Describes all the drivel that most digital cameras include...
//--------------------------------------------------------------------------
void process_EXIF (char * CharBuf, unsigned int length)
{
ImageInfo.FlashUsed = 0; // If it s from a digicam, and it used flash, it says so.
FocalplaneXRes = 0;
FocalplaneUnits = 0;
ExifImageWidth = 0;
if (ShowTags){
printf("Exif header %d bytes long\n",length);
}
{ // Check the EXIF header component
static const uchar ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
if (memcmp(CharBuf+2, ExifHeader,6)){
ErrExit("Incorrect Exif header");
}
}
if (memcmp(CharBuf+8,"II",2) == 0){
if (ShowTags) printf("Exif section in Intel order\n");
MotorolaOrder = 0;
}else{
if (memcmp(CharBuf+8,"MM",2) == 0){
if (ShowTags) printf("Exif section in Motorola order\n");
MotorolaOrder = 1;
}else{
ErrExit("Invalid Exif alignment marker.");
}
}
// Check the next two values for correctness.
if (Get16u(CharBuf+10) != 0x2a
|| Get32u(CharBuf+12) != 0x08){
ErrExit("Invalid Exif start (1)");
}
LastExifRefd = CharBuf;
// First directory starts 16 bytes in. Offsets start at 8 bytes in.
ProcessExifDir(CharBuf+16, CharBuf+8, length-6);
// This is how far the interesting (non thumbnail) part of the exif went.
ExifNonThumbnailLength = LastExifRefd - CharBuf;
// Compute the CCD width, in milimeters.
if (FocalplaneXRes != 0){
ImageInfo.CCDWidth = (float)(ExifImageWidth * FocalplaneUnits / FocalplaneXRes);
}
if (ShowTags){
printf("Thunbnail size of Exif header: %d\n",length-ExifNonThumbnailLength);
}
}
//--------------------------------------------------------------------------
// Process a EXIF marker
// Describes all the drivel that most digital cameras include...
//--------------------------------------------------------------------------
void ExifData::process_EXIF(unsigned char * CharBuf, unsigned int length)
{
ExifData::FlashUsed = 0; // If it s from a digicam, and it used flash, it says so.
FocalplaneXRes = 0;
FocalplaneUnits = 0;
ExifImageWidth = 0;
ExifImageLength = 0;
{ // Check the EXIF header component
static const uchar ExifHeader[] = "Exif\0\0";
if (memcmp(CharBuf+2, ExifHeader,6)) {
throw FatalError("Incorrect Exif header");
}
}
if (memcmp(CharBuf+8,"II",2) == 0) {
// printf("Exif section in Intel order\n");
MotorolaOrder = 0;
} else {
if (memcmp(CharBuf+8,"MM",2) == 0) {
// printf("Exif section in Motorola order\n");
MotorolaOrder = 1;
} else {
throw FatalError("Invalid Exif alignment marker.");
}
}
// Check the next two values for correctness.
if (Get16u(CharBuf+10) != 0x2a) {
throw FatalError("Invalid Exif start (1)");
}
long IFDoffset = Get32u(CharBuf+12);
LastExifRefd = CharBuf;
// First directory starts 16 bytes in. Offsets start at 8 bytes in.
ProcessExifDir(&CharBuf[8+IFDoffset], CharBuf+8, length-6, 0);
// This is how far the interesting (non thumbnail) part of the exif went.
ExifSettingsLength = LastExifRefd - CharBuf;
// Compute the CCD width, in milimeters.
if (FocalplaneXRes != 0) {
kdDebug(7034) << "ExifImageWidth " << ExifImageWidth << " FocalplaneUnits " << FocalplaneUnits << " FocalplaneXRes " << FocalplaneXRes << endl;
ExifData::CCDWidth = (float)(ExifImageWidth * FocalplaneUnits / FocalplaneXRes);
}
}
//--------------------------------------------------------------------------
// Process a EXIF marker
// Describes all the drivel that most digital cameras include...
//--------------------------------------------------------------------------
void ExifData::process_EXIF ( unsigned char * CharBuf, unsigned int length )
{
ExifData::FlashUsed = 0; // If it s from a digicam, and it used flash, it says so.
FocalplaneXRes = 0;
FocalplaneUnits = 0;
ExifImageWidth = 0;
ExifImageLength = 0;
// Check the EXIF header component
static const uchar ExifHeader[] = "Exif\0\0";
if ( memcmp ( CharBuf+2, ExifHeader,6 ) )
return ;
if ( memcmp ( CharBuf+8,"II",2 ) == 0 )
MotorolaOrder = 0;
else
{
if ( memcmp ( CharBuf+8,"MM",2 ) == 0 )
MotorolaOrder = 1;
else
return ;
}
// Check the next two values for correctness.
if ( Get16u ( CharBuf+10 ) != 0x2a || Get32u ( CharBuf+12 ) != 0x08 )
return ;
long IFDoffset = Get32u(CharBuf+12);
LastExifRefd = CharBuf;
// First directory starts 16 bytes in. Offsets start at 8 bytes in.
ProcessExifDir(&CharBuf[8+IFDoffset], CharBuf+8, length-6);
recurseLevel--;
// This is how far the interesting (non thumbnail) part of the exif went.
ExifSettingsLength = LastExifRefd - CharBuf;
// Compute the CCD width, in milimeters.
if ( FocalplaneXRes != 0 )
{
ExifData::CCDWidth = ( float ) ( ExifImageWidth * FocalplaneUnits / FocalplaneXRes );
}
}
bool Cexif::process_EXIF(unsigned char * CharBuf, unsigned int length)
{
m_exifinfo->Comments[0] = '\0';
ExifImageWidth = 0;
static const unsigned char ExifHeader[] = "Exif\0\0";
if(memcmp(CharBuf+0, ExifHeader,6))
{
strcpy(m_szLastError,"Incorrect Exif header"); return false;
}
if (memcmp(CharBuf+6,"II",2) == 0) MotorolaOrder = 0;
else
{
if (memcmp(CharBuf+6,"MM",2) == 0) MotorolaOrder = 1;
else
{
strcpy(m_szLastError,"Invalid Exif alignment marker."); return false;
}
}
if (Get16u(CharBuf+8) != 0x2a)
{
strcpy(m_szLastError,"Invalid Exif start (1)"); return false;
}
int FirstOffset = Get32u(CharBuf+10);
if (FirstOffset < 8 || FirstOffset > 16)
{
strcpy(m_szLastError,"Suspicious offset of first IFD value"); return 0;
}
unsigned char * LastExifRefd = CharBuf;
if (!ProcessExifDir(CharBuf+14, CharBuf+6, length-6, m_exifinfo, &LastExifRefd)) return false;
if (m_exifinfo->FocalplaneXRes != 0)
m_exifinfo->CCDWidth = (float)(ExifImageWidth * m_exifinfo->FocalplaneUnits / m_exifinfo->FocalplaneXRes);
return true;
}
/*--------------------------------------------------------------------------
Process one of the nested EXIF directories.
--------------------------------------------------------------------------*/
bool CxImageJPG::CxExifInfo::ProcessExifDir(unsigned char * DirStart, unsigned char * OffsetBase, unsigned ExifLength,
EXIFINFO * const pInfo, unsigned char ** const LastExifRefdP )
{
int de;
int a;
int NumDirEntries;
unsigned ThumbnailOffset = 0;
unsigned ThumbnailSize = 0;
NumDirEntries = Get16u(DirStart);
if ((DirStart+2+NumDirEntries*12) > (OffsetBase+ExifLength)){
strcpy(m_szLastError,"Illegally sized directory");
return false;
}
for (de=0;de<NumDirEntries;de++){
int Tag, Format, Components;
unsigned char * ValuePtr;
/* This actually can point to a variety of things; it must be
cast to other types when used. But we use it as a byte-by-byte
cursor, so we declare it as a pointer to a generic byte here.
*/
int ByteCount;
unsigned char * DirEntry;
DirEntry = DirStart+2+12*de;
Tag = Get16u(DirEntry);
Format = Get16u(DirEntry+2);
Components = Get32u(DirEntry+4);
if ((Format-1) >= NUM_FORMATS) {
/* (-1) catches illegal zero case as unsigned underflows
to positive large.
*/
strcpy(m_szLastError,"Illegal format code in EXIF dir");
return false;
}
ByteCount = Components * BytesPerFormat[Format];
if (ByteCount > 4){
unsigned OffsetVal;
OffsetVal = Get32u(DirEntry+8);
/* If its bigger than 4 bytes, the dir entry contains an offset.*/
if (OffsetVal+ByteCount > ExifLength){
/* Bogus pointer offset and / or bytecount value */
strcpy(m_szLastError,"Illegal pointer offset value in EXIF.");
return false;
}
ValuePtr = OffsetBase+OffsetVal;
}else{
/* 4 bytes or less and value is in the dir entry itself */
ValuePtr = DirEntry+8;
}
if (*LastExifRefdP < ValuePtr+ByteCount){
/* Keep track of last byte in the exif header that was
actually referenced. That way, we know where the
discardable thumbnail data begins.
*/
*LastExifRefdP = ValuePtr+ByteCount;
}
/* Extract useful components of tag */
switch(Tag){
case TAG_MAKE:
strncpy(pInfo->CameraMake, (char*)ValuePtr, 31);
break;
case TAG_MODEL:
strncpy(pInfo->CameraModel, (char*)ValuePtr, 39);
break;
case TAG_DATETIME_ORIGINAL:
strncpy(pInfo->DateTime, (char*)ValuePtr, 19);
break;
case TAG_USERCOMMENT:
/* Olympus has this padded with trailing spaces.
Remove these first.
*/
for (a=ByteCount;;){
a--;
if (((char*)ValuePtr)[a] == ' '){
((char*)ValuePtr)[a] = '\0';
}else{
break;
}
if (a == 0) break;
}
/* Copy the comment */
if (memcmp(ValuePtr, "ASCII",5) == 0){
for (a=5;a<10;a++){
char c;
c = ((char*)ValuePtr)[a];
if (c != '\0' && c != ' '){
strncpy(pInfo->Comments, (char*)ValuePtr+a,
199);
break;
}
}
}else{
strncpy(pInfo->Comments, (char*)ValuePtr, 199);
}
break;
case TAG_FNUMBER:
/* Simplest way of expressing aperture, so I trust it the most.
(overwrite previously computd value if there is one)
*/
pInfo->ApertureFNumber = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_APERTURE:
case TAG_MAXAPERTURE:
/* More relevant info always comes earlier, so only
use this field if we don't have appropriate aperture
information yet.
*/
if (pInfo->ApertureFNumber == 0){
pInfo->ApertureFNumber = (float)
exp(ConvertAnyFormat(ValuePtr, Format)*log(2)*0.5);
}
break;
case TAG_FOCALLENGTH:
/* Nice digital cameras actually save the focal length
as a function of how farthey are zoomed in.
*/
pInfo->FocalLength =
(float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_SUBJECT_DISTANCE:
/* Inidcates the distacne the autofocus camera is focused to.
Tends to be less accurate as distance increases.
*/
pInfo->Distance =
(float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_EXPOSURETIME:
/* Simplest way of expressing exposure time, so I
trust it most. (overwrite previously computd value
if there is one)
*/
pInfo->ExposureTime =
(float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_SHUTTERSPEED:
/* More complicated way of expressing exposure time,
so only use this value if we don't already have it
from somewhere else.
*/
if (pInfo->ExposureTime == 0){
pInfo->ExposureTime = (float)
(1/exp(ConvertAnyFormat(ValuePtr, Format)*log(2)));
}
break;
case TAG_FLASH:
if (ConvertAnyFormat(ValuePtr, Format)){
pInfo->FlashUsed = 1;
}
break;
case TAG_EXIF_IMAGELENGTH:
case TAG_EXIF_IMAGEWIDTH:
/* Use largest of height and width to deal with images
that have been rotated to portrait format.
*/
a = (int)ConvertAnyFormat(ValuePtr, Format);
if (ExifImageWidth < a) ExifImageWidth = a;
break;
case TAG_FOCALPLANEXRES:
FocalplaneXRes = ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_FOCALPLANEUNITS:
switch((int)ConvertAnyFormat(ValuePtr, Format)){
case 1: FocalplaneUnits = 25.4; break; /* 1 inch */
case 2:
/* According to the information I was using, 2
means meters. But looking at the Cannon
powershot's files, inches is the only
sensible value.
*/
FocalplaneUnits = 25.4;
break;
case 3: FocalplaneUnits = 10; break; /* 1 centimeter*/
case 4: FocalplaneUnits = 1; break; /* 1 millimeter*/
case 5: FocalplaneUnits = .001; break; /* 1 micrometer*/
}
break;
/* Remaining cases contributed by: Volker C. Schoech
([email protected])
*/
case TAG_EXPOSURE_BIAS:
pInfo->ExposureBias =
(float) ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_WHITEBALANCE:
pInfo->Whitebalance =
(int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_METERING_MODE:
pInfo->MeteringMode =
(int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_EXPOSURE_PROGRAM:
pInfo->ExposureProgram =
(int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_ISO_EQUIVALENT:
pInfo->ISOequivalent =
(int)ConvertAnyFormat(ValuePtr, Format);
if ( pInfo->ISOequivalent < 50 )
pInfo->ISOequivalent *= 200;
break;
case TAG_COMPRESSION_LEVEL:
pInfo->CompressionLevel =
(int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_THUMBNAIL_OFFSET:
ThumbnailOffset = (unsigned)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_THUMBNAIL_LENGTH:
ThumbnailSize = (unsigned)ConvertAnyFormat(ValuePtr, Format);
break;
}
if (Tag == TAG_EXIF_OFFSET || Tag == TAG_INTEROP_OFFSET){
unsigned char * SubdirStart;
SubdirStart = OffsetBase + Get32u(ValuePtr);
if (SubdirStart < OffsetBase ||
SubdirStart > OffsetBase+ExifLength){
strcpy(m_szLastError,"Illegal subdirectory link");
return false;
}
ProcessExifDir(SubdirStart, OffsetBase, ExifLength, pInfo, LastExifRefdP);
continue;
}
}
{
/* In addition to linking to subdirectories via exif tags,
there's also a potential link to another directory at the end
of each directory. This has got to be the result of a
committee!
*/
unsigned char * SubdirStart;
unsigned Offset;
Offset = Get16u(DirStart+2+12*NumDirEntries);
if (Offset){
SubdirStart = OffsetBase + Offset;
if (SubdirStart < OffsetBase
|| SubdirStart > OffsetBase+ExifLength){
strcpy(m_szLastError,"Illegal subdirectory link");
return false;
}
ProcessExifDir(SubdirStart, OffsetBase, ExifLength, pInfo, LastExifRefdP);
}
}
if (ThumbnailSize && ThumbnailOffset){
if (ThumbnailSize + ThumbnailOffset <= ExifLength){
/* The thumbnail pointer appears to be valid. Store it. */
pInfo->ThumbnailPointer = OffsetBase + ThumbnailOffset;
pInfo->ThumbnailSize = ThumbnailSize;
}
}
return true;
}
bool Cexif::ProcessExifDir(unsigned char * DirStart, unsigned char * OffsetBase, unsigned ExifLength, EXIFINFO * const m_exifinfo, unsigned char ** const LastExifRefdP )
{
int de, a, NumDirEntries;
unsigned ThumbnailOffset = 0;
unsigned ThumbnailSize = 0;
NumDirEntries = Get16u(DirStart);
if ((DirStart+2+NumDirEntries*12) > (OffsetBase+ExifLength))
{
strcpy(m_szLastError,"Illegally sized directory"); return 0;
}
for (de=0;de<NumDirEntries;de++)
{
int Tag, Format, Components;
unsigned char * ValuePtr;
int BytesCount;
unsigned char * DirEntry;
DirEntry = DirStart+2+12*de;
Tag = Get16u(DirEntry);
Format = Get16u(DirEntry+2);
Components = Get32u(DirEntry+4);
if ((Format-1) >= NUM_FORMATS)
{
strcpy(m_szLastError,"Illegal format code in EXIF dir"); return 0;
}
BytesCount = Components * BytesPerFormat[Format];
if (BytesCount > 4)
{
unsigned OffsetVal;
OffsetVal = Get32u(DirEntry+8);
if (OffsetVal+BytesCount > ExifLength)
{
strcpy(m_szLastError,"Illegal pointer offset value in EXIF."); return 0;
}
ValuePtr = OffsetBase+OffsetVal;
}
else ValuePtr = DirEntry+8;
if (*LastExifRefdP < ValuePtr+BytesCount) *LastExifRefdP = ValuePtr+BytesCount;
switch(Tag)
{
case TAG_MAKE:
strncpy(m_exifinfo->CameraMake, (char*)ValuePtr, 31);
break;
case TAG_MODEL:
strncpy(m_exifinfo->CameraModel, (char*)ValuePtr, 39);
break;
case TAG_EXIF_VERSION:
strncpy(m_exifinfo->Version,(char*)ValuePtr, 4);
break;
case TAG_DATETIME_ORIGINAL:
strncpy(m_exifinfo->DateTime, (char*)ValuePtr, 19);
break;
case TAG_USERCOMMENT:
for (a=BytesCount;;)
{
a--;
if (((char*)ValuePtr)[a] == ' ') ((char*)ValuePtr)[a] = '\0';
else break;
if (a == 0) break;
}
if (memcmp(ValuePtr, "ASCII",5) == 0)
{
for (a=5;a<10;a++)
{
char c;
c = ((char*)ValuePtr)[a];
if (c != '\0' && c != ' ')
{
strncpy(m_exifinfo->Comments, (char*)ValuePtr+a, 199);
break;
}
}
}
else strncpy(m_exifinfo->Comments, (char*)ValuePtr, 199);
break;
case TAG_FNUMBER:
m_exifinfo->ApertureFNumber = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_APERTURE:
case TAG_MAXAPERTURE:
if (m_exifinfo->ApertureFNumber == 0)
{
//m_exifinfo->ApertureFNumber = (float)exp(ConvertAnyFormat(ValuePtr, Format)*log(2)*0.5);
}
break;
case TAG_BRIGHTNESS:
m_exifinfo->Brightness = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_FOCALLENGTH:
m_exifinfo->FocalLength = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_SUBJECT_DISTANCE:
m_exifinfo->Distance = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_EXPOSURETIME:
m_exifinfo->ExposureTime = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_SHUTTERSPEED:
if (m_exifinfo->ExposureTime == 0)
{
//m_exifinfo->ExposureTime = (float) (1/exp(ConvertAnyFormat(ValuePtr, Format)*log(2)));
}
break;
case TAG_FLASH:
if ((int)ConvertAnyFormat(ValuePtr, Format) & 7) strcpy(m_exifinfo->FlashUsed,"fire");
else strcpy(m_exifinfo->FlashUsed,"not fired");
break;
case TAG_ORIENTATION:
m_exifinfo->Orient = (int)ConvertAnyFormat(ValuePtr, Format);
switch((int)ConvertAnyFormat(ValuePtr, Format))
{
case 1: strcpy(m_exifinfo->Orientation,"Top-Left"); break;
case 2: strcpy(m_exifinfo->Orientation,"Top-Right"); break;
case 3: strcpy(m_exifinfo->Orientation,"Bottom-Right"); break;
case 4: strcpy(m_exifinfo->Orientation,"Bottom-Left"); break;
case 5: strcpy(m_exifinfo->Orientation,"Left-Top"); break;
case 6: strcpy(m_exifinfo->Orientation,"Right-Top"); break;
case 7: strcpy(m_exifinfo->Orientation,"Right-Bottom"); break;
case 8: strcpy(m_exifinfo->Orientation,"Left-Bottom"); break;
default: strcpy(m_exifinfo->Orientation,"Undefined"); break;
}
break;
case TAG_EXIF_IMAGELENGTH:
case TAG_EXIF_IMAGEWIDTH:
a = (int)ConvertAnyFormat(ValuePtr, Format);
if (ExifImageWidth < a) ExifImageWidth = a;
break;
case TAG_FOCALPLANEXRES:
m_exifinfo->FocalplaneXRes = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_FOCALPLANEYRES:
m_exifinfo->FocalplaneYRes = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_RESOLUTIONUNIT:
switch((int)ConvertAnyFormat(ValuePtr, Format))
{
case 2: strcpy(m_exifinfo->ResolutionUnit,"inches"); break;
case 3: strcpy(m_exifinfo->ResolutionUnit,"centimeters"); break;
default: strcpy(m_exifinfo->ResolutionUnit,"reserved");
}
break;
case TAG_FOCALPLANEUNITS:
switch((int)ConvertAnyFormat(ValuePtr, Format))
{
case 1: m_exifinfo->FocalplaneUnits = 1.0f; break;
case 2: m_exifinfo->FocalplaneUnits = 1.0f; break;
case 3: m_exifinfo->FocalplaneUnits = 0.3937007874f; break;
case 4: m_exifinfo->FocalplaneUnits = 0.03937007874f; break;
case 5: m_exifinfo->FocalplaneUnits = 0.00003937007874f;
}
break;
case TAG_EXPOSURE_BIAS:
m_exifinfo->ExposureBias = (float) ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_WHITEBALANCE:
switch((int)ConvertAnyFormat(ValuePtr, Format))
{
case 0: strcpy(m_exifinfo->LightSource,"unknown"); break;
case 1: strcpy(m_exifinfo->LightSource,"Daylight"); break;
case 2: strcpy(m_exifinfo->LightSource,"Fluorescent"); break;
case 3: strcpy(m_exifinfo->LightSource,"Tungsten"); break;
case 17: strcpy(m_exifinfo->LightSource,"Standard light A"); break;
case 18: strcpy(m_exifinfo->LightSource,"Standard light B"); break;
case 19: strcpy(m_exifinfo->LightSource,"Standard light C"); break;
case 20: strcpy(m_exifinfo->LightSource,"D55"); break;
case 21: strcpy(m_exifinfo->LightSource,"D65"); break;
case 22: strcpy(m_exifinfo->LightSource,"D75"); break;
default: strcpy(m_exifinfo->LightSource,"other"); break;
}
break;
case TAG_METERING_MODE:
switch((int)ConvertAnyFormat(ValuePtr, Format))
{
case 0: strcpy(m_exifinfo->MeteringMode,"unknown"); break;
case 1: strcpy(m_exifinfo->MeteringMode,"Average"); break;
case 2: strcpy(m_exifinfo->MeteringMode,"Center-Weighted-Average"); break;
case 3: strcpy(m_exifinfo->MeteringMode,"Spot"); break;
case 4: strcpy(m_exifinfo->MeteringMode,"MultiSpot"); break;
case 5: strcpy(m_exifinfo->MeteringMode,"Pattern"); break;
case 6: strcpy(m_exifinfo->MeteringMode,"Partial"); break;
default: strcpy(m_exifinfo->MeteringMode,"other"); break;
}
break;
case TAG_EXPOSURE_PROGRAM:
switch((int)ConvertAnyFormat(ValuePtr, Format))
{
case 0: strcpy(m_exifinfo->ExposureProgram,"not defined"); break;
case 1: strcpy(m_exifinfo->ExposureProgram,"Manual"); break;
case 2: strcpy(m_exifinfo->ExposureProgram,"Normal program"); break;
case 3: strcpy(m_exifinfo->ExposureProgram,"Aperture priority"); break;
case 4: strcpy(m_exifinfo->ExposureProgram,"Shutter priority"); break;
case 5: strcpy(m_exifinfo->ExposureProgram,"Creative program"); break;
case 6: strcpy(m_exifinfo->ExposureProgram,"Action program"); break;
case 7: strcpy(m_exifinfo->ExposureProgram,"Portrait mode"); break;
case 8: strcpy(m_exifinfo->ExposureProgram,"Landscape mode"); break;
default: strcpy(m_exifinfo->ExposureProgram,"reserved"); break;
}
break;
case TAG_ISO_EQUIVALENT:
m_exifinfo->ISOequivalent = (int)ConvertAnyFormat(ValuePtr, Format);
if ( m_exifinfo->ISOequivalent < 50 ) m_exifinfo->ISOequivalent *= 200;
break;
case TAG_COMPRESSION_LEVEL:
m_exifinfo->CompressionLevel = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_XRESOLUTION:
m_exifinfo->Xresolution = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_YRESOLUTION:
m_exifinfo->Yresolution = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_THUMBNAIL_OFFSET:
ThumbnailOffset = (unsigned)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_THUMBNAIL_LENGTH:
ThumbnailSize = (unsigned)ConvertAnyFormat(ValuePtr, Format);
break;
}
if (Tag == TAG_EXIF_OFFSET || Tag == TAG_INTEROP_OFFSET)
{
unsigned char * SubdirStart;
SubdirStart = OffsetBase + Get32u(ValuePtr);
if (SubdirStart < OffsetBase || SubdirStart > OffsetBase+ExifLength)
{
strcpy(m_szLastError,"Illegal subdirectory link"); return 0;
}
ProcessExifDir(SubdirStart, OffsetBase, ExifLength, m_exifinfo, LastExifRefdP);
continue;
}
}
unsigned char * SubdirStart;
unsigned Offset;
Offset = Get16u(DirStart+2+12*NumDirEntries);
if (Offset)
{
SubdirStart = OffsetBase + Offset;
if (SubdirStart < OffsetBase || SubdirStart > OffsetBase+ExifLength)
{
strcpy(m_szLastError,"Illegal subdirectory link"); return 0;
}
ProcessExifDir(SubdirStart, OffsetBase, ExifLength, m_exifinfo, LastExifRefdP);
}
if (ThumbnailSize && ThumbnailOffset && m_exifinfo->Thumnailstate)
{
if (ThumbnailSize + ThumbnailOffset <= ExifLength)
{
if(FILE *tf = fopen(THUMBNAILTMPFILE, "w"))
{
fwrite( OffsetBase + ThumbnailOffset, ThumbnailSize, 1, tf);
fclose(tf);
m_exifinfo->Thumnailstate = 2;
}
}
}
return 1;
}
/*--------------------------------------------------------------------------
Process one of the nested EXIF directories.
--------------------------------------------------------------------------*/
bool CExifRead::ProcessExifDir(unsigned char * DirStart, unsigned char * OffsetBase, unsigned int ExifLength, unsigned char ** const LastExifRefdP )
{
int de;
int a;
int NumDirEntries;
unsigned ThumbnailOffset = 0;
unsigned ThumbnailSize = 0;
NumDirEntries = Get16u(DirStart);
if ((DirStart+2+NumDirEntries*12) > (OffsetBase+ExifLength))
{
#ifdef GetErrorCode
strcpy(m_szLastError,"Illegally sized directory");
#endif
return 0;
}
for (de=0;de<NumDirEntries;de++){
int Tag, Format, Components;
unsigned char * ValuePtr;
/* This actually can point to a variety of things; it must be
cast to other types when used. But we use it as a unsigned char-by-unsigned char
cursor, so we declare it as a pointer to a generic unsigned char here.
*/
int BytesCount;
unsigned char * DirEntry;
DirEntry = DirStart+2+12*de;
Tag = Get16u(DirEntry);
Format = Get16u(DirEntry+2);
Components = Get32u(DirEntry+4);
if ((Format-1) >= NUM_FORMATS)
{
#ifdef GetErrorCode
/* (-1) catches illegal zero case as unsigned underflows to positive large */
strcpy(m_szLastError,"Illegal format code in EXIF dir");
#endif
return 0;
}
BytesCount = Components * BytesPerFormat[Format];
if (BytesCount > 4){
unsigned OffsetVal;
OffsetVal = Get32u(DirEntry+8);
/* If its bigger than 4 unsigned chars, the dir entry contains an offset.*/
if (OffsetVal+BytesCount > ExifLength)
{
#ifdef GetErrorCode
/* Bogus pointer offset and / or unsigned charcount value */
strcpy(m_szLastError,"Illegal pointer offset value in EXIF.");
#endif
return 0;
}
ValuePtr = OffsetBase+OffsetVal;
}
else
{
/* 4 unsigned chars or less and value is in the dir entry itself */
ValuePtr = DirEntry+8;
}
if (*LastExifRefdP < ValuePtr+BytesCount)
{
/* Keep track of last unsigned char in the exif header that was
actually referenced. That way, we know where the
discardable thumbnail data begins.
*/
*LastExifRefdP = ValuePtr+BytesCount;
}
/* Extract useful components of tag */
switch(Tag)
{
case TAG_MAKE:
if ( m_flags & EXIF_CAMERA_MAKER)
strncpy(m_pExifInfo->CameraMake, (char*)ValuePtr, 31);
break;
case TAG_MODEL:
if ( m_flags & EXIF_CAMERA_MODEL)
strncpy_s(m_pExifInfo->CameraModel,40, (char*)ValuePtr, 39);
break;
case TAG_EXIF_VERSION:
if ( m_flags & EXIF_VERSION)
strncpy_s(m_pExifInfo->Version,5,(char*)ValuePtr, 4);
break;
case TAG_DATETIME_ORIGINAL:
if ( m_flags & EXIF_DATA_TIME)
strncpy_s(m_pExifInfo->DateTime,20, (char*)ValuePtr, 19);
break;
case TAG_USERCOMMENT:
if ( m_flags & EXIF_USER_COMMENT)
{
// Olympus has this padded with trailing spaces. Remove these first.
for ( a=BytesCount; ;)
{
a--;
if (((char*)ValuePtr)[a] == ' ')
{
((char*)ValuePtr)[a] = '\0';
}
else
{
break;
}
if (a == 0)
break;
}
/* Copy the comment */
if (memcmp(ValuePtr, "ASCII",5) == 0)
{
for (a=5;a<10;a++)
{
char c;
c = ((char*)ValuePtr)[a];
if (c != '\0' && c != ' ')
{
strncpy_s(m_pExifInfo->Comments,MAX_COMMENT, (char*)ValuePtr+a, 199);
break;
}
}
}else
{
strncpy_s(m_pExifInfo->Comments,MAX_COMMENT, (char*)ValuePtr, 199);
}
}
break;
case TAG_FNUMBER:
/* Simplest way of expressing aperture, so I trust it the most.
(overwrite previously computd value if there is one)
*/
if ( m_flags & EXIF_APERTUREF_NUMBER)
m_pExifInfo->ApertureFNumber = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_APERTURE:
case TAG_MAXAPERTURE:
/* More relevant info always comes earlier, so only
use this field if we don't have appropriate aperture
information yet.
*/
if ((m_flags & EXIF_APERTUREF_NUMBER) && m_pExifInfo->ApertureFNumber == 0)
{
m_pExifInfo->ApertureFNumber = (float)exp(ConvertAnyFormat(ValuePtr, Format)*log(2.0)*0.5);
}
break;
case TAG_BRIGHTNESS:
if ( m_flags & EXIF_BRIGHTNESS)
m_pExifInfo->Brightness = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_FOCALLENGTH:
/* Nice digital cameras actually save the focal length
as a function of how farthey are zoomed in.
*/
if ( m_flags & EXIF_FOCAL_LENGTH)
m_pExifInfo->FocalLength = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_SUBJECT_DISTANCE:
/* Inidcates the distacne the autofocus camera is focused to.
Tends to be less accurate as distance increases.
*/
if ( m_flags & EXIF_DISTANCE)
m_pExifInfo->Distance = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_EXPOSURETIME:
/* Simplest way of expressing exposure time, so I
trust it most. (overwrite previously computd value
if there is one)
*/
if ( m_flags & EXIF_EXPOSURE_TIME)
m_pExifInfo->ExposureTime = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_SHUTTERSPEED:
/* More complicated way of expressing exposure time,
so only use this value if we don't already have it
from somewhere else.
*/
if (( m_flags & EXIF_EXPOSURE_TIME) && m_pExifInfo->ExposureTime == 0)
{
m_pExifInfo->ExposureTime = (float) (1/exp(ConvertAnyFormat(ValuePtr, Format)*log(2.0)));
}
break;
case TAG_FLASH:
if ( m_flags & EXIF_FLASH_USED)
{
if ((int)ConvertAnyFormat(ValuePtr, Format) & 7)
{
m_pExifInfo->FlashUsed = 1;
}
else
{
m_pExifInfo->FlashUsed = 0;
}
}
break;
case TAG_ORIENTATION:
if ( m_flags & EXIF_ORIENTATION)
{
m_pExifInfo->Orientation = (int)ConvertAnyFormat(ValuePtr, Format);
if (m_pExifInfo->Orientation < 1 || m_pExifInfo->Orientation > 8)
{
#ifdef GetErrorCode
strcpy(m_szLastError,"Undefined rotation value");
#endif
m_pExifInfo->Orientation = 0;
}
}
break;
case TAG_EXIF_IMAGELENGTH:
case TAG_EXIF_IMAGEWIDTH:
/* Use largest of height and width to deal with images
that have been rotated to portrait format.
*/
a = (int)ConvertAnyFormat(ValuePtr, Format);
if (m_ExifImageWidth < a)
m_ExifImageWidth = a;
break;
case TAG_FOCALPLANEXRES:
if ( m_flags & EXIF_FOCALPLANE_XRES)
m_pExifInfo->FocalplaneXRes = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_FOCALPLANEYRES:
if ( m_flags & EXIF_FOCALPLANE_YRES)
m_pExifInfo->FocalplaneYRes = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_RESOLUTIONUNIT:
if ( m_flags & EXIF_RESOLUTION_UNITS)
{
switch((int)ConvertAnyFormat(ValuePtr, Format))
{
case 1: m_pExifInfo->ResolutionUnit = 1.0f; break; /* 1 inch */
case 2: m_pExifInfo->ResolutionUnit = 1.0f; break;
case 3: m_pExifInfo->ResolutionUnit = 0.3937007874f; break; /* 1 centimeter*/
case 4: m_pExifInfo->ResolutionUnit = 0.03937007874f; break; /* 1 millimeter*/
case 5: m_pExifInfo->ResolutionUnit = 0.00003937007874f; /* 1 micrometer*/
}
}
break;
case TAG_FOCALPLANEUNITS:
if ( m_flags & EXIF_FOCALPLANE_UNITS)
{
switch((int)ConvertAnyFormat(ValuePtr, Format))
{
case 1: m_pExifInfo->FocalplaneUnits = 1.0f; break; /* 1 inch */
case 2: m_pExifInfo->FocalplaneUnits = 1.0f; break;
case 3: m_pExifInfo->FocalplaneUnits = 0.3937007874f; break; /* 1 centimeter*/
case 4: m_pExifInfo->FocalplaneUnits = 0.03937007874f; break; /* 1 millimeter*/
case 5: m_pExifInfo->FocalplaneUnits = 0.00003937007874f; /* 1 micrometer*/
}
}
break;
// Remaining cases contributed by: Volker C. Schoech <schoech(at)gmx(dot)de>
case TAG_EXPOSURE_BIAS:
if ( m_flags & EXIF_EXPOSURE_BIAS)
m_pExifInfo->ExposureBias = (float) ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_WHITEBALANCE:
if ( m_flags & EXIF_WHITE_BALANCE)
m_pExifInfo->Whitebalance = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_METERING_MODE:
if ( m_flags & EXIF_METERING_MODE)
m_pExifInfo->MeteringMode = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_EXPOSURE_PROGRAM:
if ( m_flags & EXIF_EXPOSURE_PROGRAM)
m_pExifInfo->ExposureProgram = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_ISO_EQUIVALENT:
if ( m_flags & EXIF_ISO_EAUIVALENT)
{
m_pExifInfo->ISOequivalent = (int)ConvertAnyFormat(ValuePtr, Format);
if ( m_pExifInfo->ISOequivalent < 50 )
m_pExifInfo->ISOequivalent *= 200;
}
break;
case TAG_COMPRESSION_LEVEL:
if ( m_flags & EXIF_COMPRESSION_LEVEL)
m_pExifInfo->CompressionLevel = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_XRESOLUTION:
if ( m_flags & EXIF_XRESOLUTION)
m_pExifInfo->Xresolution = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_YRESOLUTION:
if ( m_flags & EXIF_YRESOLUTION)
m_pExifInfo->Yresolution = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_THUMBNAIL_OFFSET:
ThumbnailOffset = (unsigned)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_THUMBNAIL_LENGTH:
ThumbnailSize = (unsigned)ConvertAnyFormat(ValuePtr, Format);
break;
}
if (Tag == TAG_EXIF_OFFSET || Tag == TAG_INTEROP_OFFSET )
{
unsigned char * SubdirStart;
SubdirStart = OffsetBase + Get32u(ValuePtr);
if ( SubdirStart < OffsetBase ||
SubdirStart > OffsetBase + ExifLength )
{
#ifdef GetErrorCode
strcpy(m_szLastError,"Illegal subdirectory link");
#endif
return 0;
}
ProcessExifDir(SubdirStart, OffsetBase, ExifLength, LastExifRefdP);
continue;
}
}
{
/* In addition to linking to subdirectories via exif tags,
there's also a potential link to another directory at the end
of each directory. This has got to be the result of a
committee!
*/
unsigned char * SubdirStart;
unsigned Offset;
Offset = Get32u(DirStart+2+12*NumDirEntries);
if (Offset > 0)
{
SubdirStart = OffsetBase + Offset;
if (SubdirStart < OffsetBase
|| SubdirStart > OffsetBase+ExifLength)
{
#ifdef GetErrorCode
strcpy(m_szLastError,"Illegal subdirectory link");
#endif
return 0;
}
ProcessExifDir(SubdirStart, OffsetBase, ExifLength, LastExifRefdP);
}
}
if (ThumbnailSize && ThumbnailOffset)
{
if (ThumbnailSize + ThumbnailOffset <= ExifLength)
{
if ( m_pExifInfo->pThumbnailPointer != NULL)
{
delete m_pExifInfo->pThumbnailPointer;
}
/* The thumbnail pointer appears to be valid. Store it. */
m_pExifInfo->pThumbnailPointer = OffsetBase + ThumbnailOffset;
m_pExifInfo->ThumbnailOffset = ThumbnailOffset;
m_pExifInfo->ThumbnailSize = ThumbnailSize;
}
}
return 1;
}
//--------------------------------------------------------------------------
// Process one of the nested EXIF directories.
//--------------------------------------------------------------------------
void ExifData::ProcessExifDir(unsigned char * DirStart, unsigned char * OffsetBase, unsigned ExifLength, unsigned NestingLevel)
{
int de;
int a;
int NumDirEntries;
unsigned ThumbnailOffset = 0;
unsigned ThumbnailSize = 0;
if ( NestingLevel > 4)
throw FatalError("Maximum directory nesting exceeded (corrupt exif header)");
NumDirEntries = Get16u(DirStart);
#define DIR_ENTRY_ADDR(Start, Entry) (Start+2+12*(Entry))
{
unsigned char * DirEnd;
DirEnd = DIR_ENTRY_ADDR(DirStart, NumDirEntries);
if (DirEnd+4 > (OffsetBase+ExifLength)) {
if (DirEnd+2 == OffsetBase+ExifLength || DirEnd == OffsetBase+ExifLength) {
// Version 1.3 of jhead would truncate a bit too much.
// This also caught later on as well.
} else {
// Note: Files that had thumbnails trimmed with jhead 1.3 or earlier
// might trigger this.
throw FatalError("Illegally sized directory");
}
}
if (DirEnd < LastExifRefd) LastExifRefd = DirEnd;
}
for (de=0; de<NumDirEntries; de++) {
int Tag, Format, Components;
unsigned char * ValuePtr;
unsigned ByteCount;
char * DirEntry;
DirEntry = (char *)DIR_ENTRY_ADDR(DirStart, de);
Tag = Get16u(DirEntry);
Format = Get16u(DirEntry+2);
Components = Get32u(DirEntry+4);
if ((Format-1) >= NUM_FORMATS) {
// (-1) catches illegal zero case as unsigned underflows to positive large.
throw FatalError("Illegal format code in EXIF dir");
}
if ((unsigned)Components > 0x10000) {
throw FatalError("Illegal number of components for tag");
continue;
}
ByteCount = Components * BytesPerFormat[Format];
if (ByteCount > 4) {
unsigned OffsetVal;
OffsetVal = Get32u(DirEntry+8);
// If its bigger than 4 bytes, the dir entry contains an offset.
if (OffsetVal+ByteCount > ExifLength) {
// Bogus pointer offset and / or bytecount value
//printf("Offset %d bytes %d ExifLen %d\n",OffsetVal, ByteCount, ExifLength);
throw FatalError("Illegal pointer offset value in EXIF");
}
ValuePtr = OffsetBase+OffsetVal;
} else {
// 4 bytes or less and value is in the dir entry itself
ValuePtr = (unsigned char *)DirEntry+8;
}
if (LastExifRefd < ValuePtr+ByteCount) {
// Keep track of last byte in the exif header that was actually referenced.
// That way, we know where the discardable thumbnail data begins.
LastExifRefd = ValuePtr+ByteCount;
}
// Extract useful components of tag
switch(Tag) {
case TAG_MAKE:
ExifData::CameraMake = QString::fromLatin1((const char*)ValuePtr, 31);
break;
case TAG_MODEL:
ExifData::CameraModel = QString::fromLatin1((const char*)ValuePtr, 39);
break;
case TAG_ORIENTATION:
Orientation = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_DATETIME_ORIGINAL:
DateTime = QString::fromLatin1((const char*)ValuePtr, 19);
break;
case TAG_USERCOMMENT:
// Olympus has this padded with trailing spaces. Remove these first.
for (a=ByteCount;;) {
a--;
if ((ValuePtr)[a] == ' ') {
(ValuePtr)[a] = '\0';
} else {
break;
}
if (a == 0) break;
}
// Copy the comment
if (memcmp(ValuePtr, "ASCII",5) == 0) {
for (a=5; a<10; a++) {
int c;
c = (ValuePtr)[a];
if (c != '\0' && c != ' ') {
UserComment = QString::fromLatin1((const char*)(a+ValuePtr), 199);
break;
}
}
} else {
UserComment = QString::fromLatin1((const char*)ValuePtr, 199);
}
break;
case TAG_FNUMBER:
// Simplest way of expressing aperture, so I trust it the most.
// (overwrite previously computd value if there is one)
ExifData::ApertureFNumber = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_APERTURE:
case TAG_MAXAPERTURE:
// More relevant info always comes earlier, so only use this field if we don't
// have appropriate aperture information yet.
if (ExifData::ApertureFNumber == 0) {
ExifData::ApertureFNumber
= (float)exp(ConvertAnyFormat(ValuePtr, Format)*log(2.0)*0.5);
}
break;
case TAG_FOCALLENGTH:
// Nice digital cameras actually save the focal length as a function
// of how far they are zoomed in.
ExifData::FocalLength = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_SUBJECT_DISTANCE:
// Inidcates the distacne the autofocus camera is focused to.
// Tends to be less accurate as distance increases.
ExifData::Distance = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_EXPOSURETIME:
// Simplest way of expressing exposure time, so I trust it most.
// (overwrite previously computd value if there is one)
ExifData::ExposureTime = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_SHUTTERSPEED:
// More complicated way of expressing exposure time, so only use
// this value if we don't already have it from somewhere else.
if (ExifData::ExposureTime == 0) {
ExifData::ExposureTime
= (float)(1/exp(ConvertAnyFormat(ValuePtr, Format)*log(2.0)));
}
break;
case TAG_FLASH:
ExifData::FlashUsed = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_EXIF_IMAGELENGTH:
ExifImageLength = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_EXIF_IMAGEWIDTH:
ExifImageWidth = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_FOCALPLANEXRES:
FocalplaneXRes = ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_FOCALPLANEUNITS:
switch((int)ConvertAnyFormat(ValuePtr, Format)) {
case 1:
FocalplaneUnits = 25.4;
break; // inch
case 2:
// According to the information I was using, 2 means meters.
// But looking at the Cannon powershot's files, inches is the only
// sensible value.
FocalplaneUnits = 25.4;
break;
case 3:
FocalplaneUnits = 10;
break; // centimeter
case 4:
FocalplaneUnits = 1;
break; // milimeter
case 5:
FocalplaneUnits = .001;
break; // micrometer
}
break;
// Remaining cases contributed by: Volker C. Schoech ([email protected])
case TAG_EXPOSURE_BIAS:
ExifData::ExposureBias = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_WHITEBALANCE:
ExifData::Whitebalance = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_METERING_MODE:
ExifData::MeteringMode = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_EXPOSURE_PROGRAM:
ExifData::ExposureProgram = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_ISO_EQUIVALENT:
ExifData::ISOequivalent = (int)ConvertAnyFormat(ValuePtr, Format);
if ( ExifData::ISOequivalent < 50 ) ExifData::ISOequivalent *= 200;
break;
case TAG_COMPRESSION_LEVEL:
ExifData::CompressionLevel = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_THUMBNAIL_OFFSET:
ThumbnailOffset = (unsigned)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_THUMBNAIL_LENGTH:
ThumbnailSize = (unsigned)ConvertAnyFormat(ValuePtr, Format);
break;
}
if (Tag == TAG_EXIF_OFFSET || Tag == TAG_INTEROP_OFFSET) {
unsigned char * SubdirStart;
SubdirStart = OffsetBase + Get32u(ValuePtr);
if (SubdirStart <= OffsetBase || SubdirStart >= OffsetBase+ExifLength) {
throw FatalError("Illegal subdirectory link");
}
ProcessExifDir(SubdirStart, OffsetBase, ExifLength, NestingLevel+1);
continue;
}
}
{
// In addition to linking to subdirectories via exif tags,
// there's also a potential link to another directory at the end of each
// directory. this has got to be the result of a comitee!
unsigned char * SubdirStart;
unsigned Offset;
if (DIR_ENTRY_ADDR(DirStart, NumDirEntries) + 4 <= OffsetBase+ExifLength) {
Offset = Get32u(DIR_ENTRY_ADDR(DirStart, NumDirEntries));
// There is at least one jpeg from an HP camera having an Offset of almost MAXUINT.
// Adding OffsetBase to it produces an overflow, so compare with ExifLength here.
// See http://bugs.kde.org/show_bug.cgi?id=54542
if (Offset && Offset < ExifLength) {
SubdirStart = OffsetBase + Offset;
if (SubdirStart > OffsetBase+ExifLength) {
if (SubdirStart < OffsetBase+ExifLength+20) {
// Jhead 1.3 or earlier would crop the whole directory!
// As Jhead produces this form of format incorrectness,
// I'll just let it pass silently
kdDebug(7034) << "Thumbnail removed with Jhead 1.3 or earlier\n";
} else {
throw FatalError("Illegal subdirectory link 2");
}
} else {
if (SubdirStart <= OffsetBase+ExifLength) {
ProcessExifDir(SubdirStart, OffsetBase, ExifLength, NestingLevel+1);
}
}
}
} else {
// The exif header ends before the last next directory pointer.
}
}
if (ThumbnailSize && ThumbnailOffset) {
if (ThumbnailSize + ThumbnailOffset < ExifLength) {
// The thumbnail pointer appears to be valid. Store it.
Thumbnail.loadFromData(OffsetBase + ThumbnailOffset, ThumbnailSize, "JPEG");
}
}
}
//--------------------------------------------------------------------------
// Process one of the nested EXIF directories.
//--------------------------------------------------------------------------
static void ProcessExifDir(char * DirStart, char * OffsetBase, unsigned ExifLength)
{
int de;
int a;
int NumDirEntries;
NumDirEntries = Get16u(DirStart);
if ((DirStart+2+NumDirEntries*12) > (OffsetBase+ExifLength)){
ErrExit("Illegally sized directory");
}
if (ShowTags){
printf("Directory with %d entries\n",NumDirEntries);
}
for (de=0;de<NumDirEntries;de++){
int Tag, Format, Components;
char * ValuePtr;
int ByteCount;
char * DirEntry;
DirEntry = DirStart+2+12*de;
Tag = Get16u(DirEntry);
Format = Get16u(DirEntry+2);
Components = Get32u(DirEntry+4);
if ((Format-1) >= NUM_FORMATS) {
// (-1) catches illegal zero case as unsigned underflows to positive large.
ErrExit("Illegal format code in EXIF dir");
}
ByteCount = Components * BytesPerFormat[Format];
if (ByteCount > 4){
unsigned OffsetVal;
OffsetVal = Get32u(DirEntry+8);
// If its bigger than 4 bytes, the dir entry contains an offset.
if (OffsetVal+ByteCount > ExifLength){
// Bogus pointer offset and / or bytecount value
printf("Offset %d bytes %d ExifLen %d\n",OffsetVal, ByteCount, ExifLength);
ErrExit("Illegal pointer offset value in EXIF");
}
ValuePtr = OffsetBase+OffsetVal;
}else{
// 4 bytes or less and value is in the dir entry itself
ValuePtr = DirEntry+8;
}
if (LastExifRefd < ValuePtr+ByteCount){
// Keep track of last byte in the exif header that was actually referenced.
// That way, we know where the discardable thumbnail data begins.
LastExifRefd = ValuePtr+ByteCount;
}
if (ShowTags){
// Show tag name
for (a=0;;a++){
if (TagTable[a].Tag == 0){
printf(" Unknown Tag %04x Value = ", Tag);
break;
}
if (TagTable[a].Tag == Tag){
printf(" %s = ",TagTable[a].Desc);
break;
}
}
// Show tag value.
switch(Format){
case FMT_UNDEFINED:
// Undefined is typically an ascii string.
case FMT_STRING:
// String arrays printed without function call (different from int arrays)
printf("\"");
for (a=0;a<ByteCount;a++){
if (isprint((ValuePtr)[a])){
putchar((ValuePtr)[a]);
}
}
printf("\"\n");
break;
default:
// Handle arrays of numbers later (will there ever be?)
PrintFormatNumber(ValuePtr, Format);
}
}
// Extract useful components of tag
switch(Tag){
case TAG_MAKE:
strncpy(ImageInfo.CameraMake, ValuePtr, 31);
break;
case TAG_MODEL:
strncpy(ImageInfo.CameraModel, ValuePtr, 39);
break;
case TAG_DATETIME_ORIGINAL:
strncpy(ImageInfo.DateTime, ValuePtr, 19);
break;
case TAG_USERCOMMENT:
// Olympus has this padded with trailing spaces. Remove these first.
for (a=ByteCount;;){
a--;
if ((ValuePtr)[a] == ' '){
(ValuePtr)[a] = '\0';
}else{
break;
}
if (a == 0) break;
}
// Copy the comment
if (memcmp(ValuePtr, "ASCII",5) == 0){
for (a=5;a<10;a++){
int c;
c = (ValuePtr)[a];
if (c != '\0' && c != ' '){
strncpy(ImageInfo.Comments, a+ValuePtr, 199);
break;
}
}
}else{
strncpy(ImageInfo.Comments, ValuePtr, 199);
}
break;
case TAG_FNUMBER:
// Simplest way of expressing aperture, so I trust it the most.
// (overwrite previously computd value if there is one)
ImageInfo.ApertureFNumber = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_APERTURE:
case TAG_MAXAPERTURE:
// More relevant info always comes earlier, so only use this field if we don't
// have appropriate aperture information yet.
if (ImageInfo.ApertureFNumber == 0){
ImageInfo.ApertureFNumber
= (float)exp(ConvertAnyFormat(ValuePtr, Format)*log(2)*0.5);
}
break;
case TAG_FOCALLENGTH:
// Nice digital cameras actually save the focal length as a function
// of how farthey are zoomed in.
ImageInfo.FocalLength = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_SUBJECT_DISTANCE:
// Inidcates the distacne the autofocus camera is focused to.
// Tends to be less accurate as distance increases.
ImageInfo.Distance = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_EXPOSURETIME:
// Simplest way of expressing exposure time, so I trust it most.
// (overwrite previously computd value if there is one)
ImageInfo.ExposureTime = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_SHUTTERSPEED:
// More complicated way of expressing exposure time, so only use
// this value if we don't already have it from somewhere else.
if (ImageInfo.ExposureTime == 0){
ImageInfo.ExposureTime
= (float)(1/exp(ConvertAnyFormat(ValuePtr, Format)*log(2)));
}
break;
case TAG_FLASH:
if (ConvertAnyFormat(ValuePtr, Format)){
ImageInfo.FlashUsed = 1;
}
break;
case TAG_EXIF_IMAGELENGTH:
case TAG_EXIF_IMAGEWIDTH:
// Use largest of height and width to deal with images that have been
// rotated to portrait format.
a = (int)ConvertAnyFormat(ValuePtr, Format);
if (ExifImageWidth < a) ExifImageWidth = a;
break;
case TAG_FOCALPLANEXRES:
FocalplaneXRes = ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_FOCALPLANEUNITS:
switch((int)ConvertAnyFormat(ValuePtr, Format)){
case 1: FocalplaneUnits = 25.4; break; // inch
case 2:
// According to the information I was using, 2 means meters.
// But looking at the Cannon powershot's files, inches is the only
// sensible value.
FocalplaneUnits = 25.4;
break;
case 3: FocalplaneUnits = 10; break; // centimeter
case 4: FocalplaneUnits = 1; break; // milimeter
case 5: FocalplaneUnits = .001; break; // micrometer
}
break;
// Remaining cases contributed by: Volker C. Schoech ([email protected])
case TAG_EXPOSURE_BIAS:
ImageInfo.ExposureBias = (float)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_WHITEBALANCE:
ImageInfo.Whitebalance = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_METERING_MODE:
ImageInfo.MeteringMode = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_EXPOSURE_PROGRAM:
ImageInfo.ExposureProgram = (int)ConvertAnyFormat(ValuePtr, Format);
break;
case TAG_ISO_EQUIVALENT:
ImageInfo.ISOequivalent = (int)ConvertAnyFormat(ValuePtr, Format);
if ( ImageInfo.ISOequivalent < 80 ) ImageInfo.ISOequivalent *= 200;
break;
case TAG_COMPRESSION_LEVEL:
ImageInfo.CompressionLevel = (int)ConvertAnyFormat(ValuePtr, Format);
break;
}
if (Tag == TAG_EXIF_OFFSET || Tag == TAG_INTEROP_OFFSET){
char * SubdirStart;
SubdirStart = OffsetBase + Get32u(ValuePtr);
if (SubdirStart < OffsetBase || SubdirStart > OffsetBase+ExifLength){
ErrExit("Illegal subdirectory link");
}
ProcessExifDir(SubdirStart, OffsetBase, ExifLength);
continue;
}
}
}
