function get_Special_Tag_Text_Value($Tag, $Tag_Definitions_Name)
{
// Check what type of IFD is being decoded
if ($Tag_Definitions_Name == "TIFF") {
// This is a TIFF IFD (bottom level)
// Check what tag number the IFD entry has.
switch ($Tag['Tag Number']) {
case 530:
// YCbCr Sub Sampling Entry
// Data contains two numerical values
if ($Tag['Data'][0] == 2 && $Tag['Data'][1] == 1) {
// Values are 2,1 - hence YCbCr 4:2:2
return "YCbCr 4:2:2 ratio of chrominance components to the luminance components";
} elseif ($Tag['Data'][0] == 2 && $Tag['Data'][1] == 2) {
// Values are 2,2 - hence YCbCr 4:2:0
return "YCbCr 4:2:0 ratio of chrominance components to the luminance components";
} else {
// Other values are unknown
return "Unknown Reserved value (" . $Tag['Data'][0] . ")";
}
break;
default:
return FALSE;
}
} else {
if ($Tag_Definitions_Name == "EXIF") {
// This is an EXIF IFD
// Check what tag number the IFD entry has.
switch ($Tag['Tag Number']) {
case 37121:
// Components configuration
// Data contains 4 numerical values indicating component type
$output_str = "";
// Cycle through each component
for ($Num = 0; $Num < 4; $Num++) {
// Construct first part of text string
$output_str .= "Component " . ($Num + 1) . ": ";
// Construct second part of text string via
// lookup using numerical value
$value = ord($Tag['Data'][$Num]);
switch ($value) {
case 0:
$output_str .= "Does not exist\n";
break;
case 1:
$output_str .= "Y (Luminance)\n";
break;
case 2:
$output_str .= "Cb (Chroma minus Blue)\n";
break;
case 3:
$output_str .= "Cr (Chroma minus Red)\n";
break;
case 4:
$output_str .= "Red\n";
break;
case 5:
$output_str .= "Green\n";
break;
case 6:
$output_str .= "Blue\n";
break;
default:
$output_str .= "Unknown value {$value}\n";
}
}
// Return the completed string
return $output_str;
break;
case 41730:
// Colour Filter Array Pattern
// The first two characters are a SHORT for Horizontal repeat pixel unit -
$n_max = get_IFD_Data_Type(substr($Tag['Data'], 0, 2), 3, $Tag['Byte Align']);
// The next two characters are a SHORT for Vertical repeat pixel unit -
$m_max = get_IFD_Data_Type(substr($Tag['Data'], 2, 2), 3, $Tag['Byte Align']);
// At least one camera type appears to have byte reversed values for N_Max and M_Max
// Check if they need reversing
if ($n_max > 256) {
$n_max = $n_max / 256 + 256 * ($n_max % 256);
}
if ($m_max > 256) {
$m_max = $m_max / 256 + 256 * ($m_max % 256);
}
$output_str = "";
// Cycle through all the elements in the resulting 2 dimensional array,
for ($m = 1; $m <= $m_max; $m++) {
for ($n = 1; $n <= $n_max; $n++) {
// Append text from a lookup table according to
// the value read for this element
switch (ord($Tag['Data'][$n_max * ($m - 1) + $n + 3])) {
case 0:
$output_str .= "RED ";
break;
case 1:
$output_str .= "GREEN ";
break;
case 2:
$output_str .= "BLUE ";
break;
case 3:
$output_str .= "CYAN ";
break;
case 4:
$output_str .= "MAGENTA ";
break;
case 5:
$output_str .= "YELLOW ";
break;
case 6:
$output_str .= "WHITE ";
break;
default:
$output_str .= "Unknown ";
break;
}
}
$output_str .= "\n";
}
// Return the resulting string
return $output_str;
break;
default:
return FALSE;
}
} else {
// Unknown IFD type, see if it is part of a makernote
return get_Makernote_Text_Value($Tag, $Tag_Definitions_Name);
}
}
}
function Decode_PIM($tag, $Tag_Definitions_Name)
{
// Create a new EXIF tag for the output
$newtag = $tag;
// Check that this tag is for Print Image Matching Info
if ($tag['Type'] == "PIM") {
// Check that the data starts with PrintIM
if (substr($tag['Data'], 0, 8) == "PrintIM") {
// Find the end of the version string
if (($ver_pos = strpos($tag['Data'], "", 8)) == -1) {
// couldn't find the start of the version string
return $newtag;
}
// Create an array to receive the Data
$newtag['Data'] = array();
// Extract the PrintIM version
$newtag['Data']['Version'] = substr($tag['Data'], 8, $ver_pos - 8);
// Skip the position over the version
$count_pos = $ver_pos + 2;
// Extract the count of tags - 2 bytes
$PI_tag_count = get_IFD_Data_Type(substr($tag['Data'], $count_pos, 2), 3, $tag['Byte Align']);
// Panasonic have put an extra Null after the Version, which
// causes the tag count to be wrong -
// check if it is zero - i.e. possibly wrong
if ($PI_tag_count == 0) {
// Tag count is zero - try moving the position by one,
// then re-extracting the count
$count_pos++;
$PI_tag_count = get_IFD_Data_Type(substr($tag['Data'], $count_pos, 2), 3, $tag['Byte Align']);
}
// Extract the data part of the PrintIM block
$data_part = substr($tag['Data'], $count_pos + 2);
// Cycle through each tag
for ($a = 0; $a < $PI_tag_count; $a++) {
// Read the tag number - 2 bytes
$PI_tag = get_IFD_Data_Type(substr($data_part, $a * 6, 2), 3, $tag['Byte Align']);
// Read the tag data - 4 bytes
$newtag['Data'][] = array('Tag Number' => $PI_tag, 'Data' => substr($data_part, $a * 6 + 2, 4), 'Decoded' => False);
}
}
}
// Return the updated tag
return $newtag;
}
function get_Minolta_Text_Value($Exif_Tag, $Tag_Definitions_Name)
{
// Check that this Tag uses Olympus type tags - otherwise it cannot be processed here
if ($Tag_Definitions_Name !== "Olympus") {
// Not Olympus Tags - cannot be processed here
return FALSE;
}
// Process the tag acording to it's tag number, to produce a text value
if ($Exif_Tag['Tag Number'] == 0x1 || $Exif_Tag['Tag Number'] == 0x3) {
// Create the output string
$output_str = "";
// Cycle through each camera setting record which are 4 byte Longs
for ($i = 1; $i * 4 <= strlen($Exif_Tag['Data']); $i++) {
// Exract the current 4 byte Long value (Motorola byte alignment)
$value = get_IFD_Data_Type(substr($Exif_Tag['Data'], ($i - 1) * 4, 4), 4, "MM");
// Corrupt settings can cause huge values, which automatically get
// put into floating point variables instead of integer variables
// Hence Check that this is an integer, as problems will occur if it isn't
if (is_integer($value)) {
// Check if the current setting number is in the Definitions array
if (array_key_exists($i, $GLOBALS["Minolta_Camera_Setting_Definitions"]) === TRUE) {
// Setting is in definitions array
// Get some of the information from the settings definitions array
$tagname = $GLOBALS["Minolta_Camera_Setting_Definitions"][$i]['Name'];
$units = "";
if (array_key_exists('Units', $GLOBALS["Minolta_Camera_Setting_Definitions"][$i])) {
$units = $GLOBALS["Minolta_Camera_Setting_Definitions"][$i]['Units'];
}
// Check what type of field the setting is, and process accordingly
if ($GLOBALS["Minolta_Camera_Setting_Definitions"][$i]['Type'] == "Lookup") {
// This is a lookup table field
// Check if the value read is in the lookup table
if (array_key_exists($value, $GLOBALS["Minolta_Camera_Setting_Definitions"][$i])) {
// Value is in the lookup table - Add it to the text
$output_str .= $tagname . ": " . $GLOBALS["Minolta_Camera_Setting_Definitions"][$i][$value] . "\n";
} else {
// Value is Not in the lookup table
// Add a message if the user has requested to see unknown tags
if ($GLOBALS['HIDE_UNKNOWN_TAGS'] == FALSE) {
$output_str .= $tagname . ": Unknown Reserved Value {$value}\n";
}
}
} else {
if ($GLOBALS["Minolta_Camera_Setting_Definitions"][$i]['Type'] == "Numeric") {
// This is a numeric type add it as is to the output, with units
$output_str .= $tagname . ": {$value} {$units}\n";
} else {
if ($GLOBALS["Minolta_Camera_Setting_Definitions"][$i]['Type'] == "Special") {
// This is a special setting, Process it according to the setting number
switch ($i) {
case 9:
// Apex Film Speed Value
$output_str .= $tagname . ": " . ($value / 8 - 1) . " ( ISO " . pow(2, $value / 8 - 1) * 3.125 . " )\n";
break;
case 10:
// Apex Shutter Speed Time Value
$output_str .= $tagname . ": " . ($value / 8 - 6);
if ($value == 8) {
$output_str .= " ( 30 seconds )\n";
} else {
$output_str .= " ( " . pow(2, (48 - $value) / 8) . " seconds )\n";
}
break;
case 11:
// Apex Aperture Value
$output_str .= $tagname . ": " . ($value / 8 - 1) . " ( F Stop: " . pow(2, $value / 16 - 0.5) . " )\n";
break;
case 14:
// Exposure Compensation
$output_str .= $tagname . ": " . ($value / 3 - 2) . " {$units}\n";
break;
case 17:
// Interval Length
$output_str .= $tagname . ": " . ($value + 1) . " {$units}\n";
break;
case 19:
// Focal Length
$output_str .= $tagname . ": " . $value / 256 . " {$units}\n";
break;
case 22:
// Date
$output_str .= $tagname . ": " . sprintf("%d/%d/%d", $value % 256, floor(($value - floor($value / 65536) * 65536) / 256), floor($value / 65536)) . " {$units}\n";
break;
case 23:
// Time
$output_str .= $tagname . ": " . sprintf("%2d:%02d:%02d", floor($value / 65536), floor(($value - floor($value / 65536) * 65536) / 256), $value % 256) . " {$units}\n";
break;
case 24:
// Max Aperture at this focal length
$output_str .= $tagname . ": F" . pow(2, $value / 16 - 0.5) . " {$units}\n";
break;
case 29:
// White Balance Red
// White Balance Red
case 30:
// White Balance Green
// White Balance Green
case 31:
// White Balance Blue
$output_str .= $tagname . ": " . $value / 256 . " {$units}\n";
break;
case 32:
// Saturation
// Saturation
case 33:
// Contrast
$output_str .= $tagname . ": " . ($value - 3) . " {$units}\n";
break;
case 36:
// Flash Compensation
$output_str .= $tagname . ": " . ($value - 6) / 3 . " {$units}\n";
break;
case 42:
// Color Filter
$output_str .= $tagname . ": " . ($value - 3) . " {$units}\n";
break;
case 45:
// Apex Brightness Value
$output_str .= $tagname . ": " . ($value / 8 - 6) . " {$units}\n";
break;
default:
// Unknown Special Setting
// If user has requested to see the unknown tags, then add the setting to the output
if ($GLOBALS['HIDE_UNKNOWN_TAGS'] == FALSE) {
$output_str .= "Unknown Special Tag: {$tagname}, Value: {$value} {$units}\n";
}
break;
}
} else {
// Unknown Setting Type
// If user has requested to see the unknown tags, then add the setting to the output
if ($GLOBALS['HIDE_UNKNOWN_TAGS'] == FALSE) {
$output_str .= "Unknown Tag Type Tag {$i}, Value: " . $value . "\n";
}
}
}
}
} else {
// Unknown Setting
// If user has requested to see the unknown tags, then add the setting to the output
if ($GLOBALS['HIDE_UNKNOWN_TAGS'] == FALSE) {
$output_str .= "Unknown Minolta Camera Setting Tag {$i}, Value: " . $value . "\n";
}
}
}
}
// Return the text string
return $output_str;
} else {
if ($Exif_Tag['Tag Number'] == 0x88 || $Exif_Tag['Tag Number'] == 0x81) {
// Konica/Minolta Thumbnail
return "Thumbnail";
} else {
return FALSE;
}
}
}
