<?php/******************************************************************************** Filename:     JFIF.php** Description:  Provides functions for reading and writing information to/from*               JPEG File Interchange Format (JFIF) segments and*               JFIF Extension (JFXX) segments within a JPEG file.** Author:       Evan Hunter** Date:         24/7/2004** Project:      PHP JPEG Metadata Toolkit** Revision:     1.11** Changes:      1.00 -> 1.11 : changed Interpret_JFXX_to_HTML to allow thumbnail links to work when*                              toolkit is portable across directories** URL:          http://electronics.ozhiker.com** Copyright:    Copyright Evan Hunter 2004** License:      This file is part of the PHP JPEG Metadata Toolkit.**               The PHP JPEG Metadata Toolkit is free software; you can*               redistribute it and/or modify it under the terms of the*               GNU General Public License as published by the Free Software*               Foundation; either version 2 of the License, or (at your*               option) any later version.**               The PHP JPEG Metadata Toolkit is distributed in the hope*               that it will be useful, but WITHOUT ANY WARRANTY; without*               even the implied warranty of MERCHANTABILITY or FITNESS*               FOR A PARTICULAR PURPOSE.  See the GNU General Public License*               for more details.**               You should have received a copy of the GNU General Public*               License along with the PHP JPEG Metadata Toolkit; if not,*               write to the Free Software Foundation, Inc., 59 Temple*               Place, Suite 330, Boston, MA  02111-1307  USA**               If you require a different license for commercial or other*               purposes, please contact the author: evan@ozhiker.com*******************************************************************************/include_once 'pjmt_utils.php';          // Change: as of version 1.11 - added to allow directory portability/******************************************************************************** Function:     get_JFIF** Description:  Retrieves information from a JPEG File Interchange Format (JFIF)*               segment and returns it in an array. Uses information supplied by*               the get_jpeg_header_data function** Parameters:   jpeg_header_data - a JPEG header data array in the same format*                                  as from get_jpeg_header_data** Returns:      JFIF_data - an array of JFIF data*               FALSE - if a JFIF segment could not be found*******************************************************************************/function get_JFIF( $jpeg_header_data ){        //Cycle through the header segments        for( $i = 0; $i < count( $jpeg_header_data ); $i++ )        {                // If we find an APP0 header,                if ( strcmp ( $jpeg_header_data[$i]['SegName'], "APP0" ) == 0 )                {                        // And if it has the JFIF label,                        if( strncmp ( $jpeg_header_data[$i]['SegData'], "JFIF\x00", 5) == 0 )                        {                                // Found a JPEG File Interchange Format (JFIF) Block                                // unpack the JFIF data from the incoming string                                // First is the JFIF label string                                // Then a two byte version number                                // Then a byte, units identifier, ( 0 = aspect ration, 1 = dpi, 2 = dpcm)                                // Then a two byte int X-Axis pixel Density (resolution)                                // Then a two byte int Y-Axis pixel Density (resolution)                                // Then a byte X-Axis JFIF thumbnail size                                // Then a byte Y-Axis JFIF thumbnail size                                // Then the uncompressed RGB JFIF thumbnail data                                $JFIF_data = unpack( 'a5JFIF/C2Version/CUnits/nXDensity/nYDensity/CThumbX/CThumbY/a*ThumbData', $jpeg_header_data[$i]['SegData'] );                                return $JFIF_data;                        }                }        }        return FALSE;}/******************************************************************************* End of Function:     get_JFIF******************************************************************************//******************************************************************************** Function:     put_JFIF** Description:  Creates a new JFIF segment from an array of JFIF data in the*               same format as would be retrieved from get_JFIF, and inserts*               this segment into the supplied JPEG header array** Parameters:   jpeg_header_data - a JPEG header data array in the same format*                                  as from get_jpeg_header_data, into which the*                                  new JFIF segment will be put*               new_JFIF_array - a JFIF information array in the same format as*                                from get_JFIF, to create the new segment** Returns:      jpeg_header_data - the JPEG header data array with the new*                                  JFIF segment added*******************************************************************************/function put_JFIF( $jpeg_header_data, $new_JFIF_array ){        // pack the JFIF data into its proper format for a JPEG file        $packed_data = pack( 'a5CCCnnCCa*',"JFIF\x00", $new_JFIF_array['Version1'], $new_JFIF_array['Version2'], $new_JFIF_array['Units'], $new_JFIF_array['XDensity'], $new_JFIF_array['YDensity'], $new_JFIF_array['ThumbX'], $new_JFIF_array['ThumbY'], $new_JFIF_array['ThumbData'] );        //Cycle through the header segments        for( $i = 0; $i < count( $jpeg_header_data ); $i++ )        {                // If we find an APP0 header,                if ( strcmp ( $jpeg_header_data[$i]['SegName'], "APP0" ) == 0 )                {                        // And if it has the JFIF label,                        if( strncmp ( $jpeg_header_data[$i]['SegData'], "JFIF\x00", 5) == 0 )                        {                                // Found a preexisting JFIF block - Replace it with the new one and return.                                $jpeg_header_data[$i]['SegData'] = $packed_data;                                return $jpeg_header_data;                        }                }        }        // No preexisting JFIF block found, insert a new one at the start of the header data.        array_splice($jpeg_header_data, 0 , 0, array( array(   "SegType" => 0xE0,                                                                "SegName" => "APP0",                                                                "SegDesc" => $GLOBALS[ "JPEG_Segment_Descriptions" ][ 0xE0 ],                                                                "SegData" => $packed_data ) ) );        return $jpeg_header_data;}/******************************************************************************* End of Function:     put_JFIF******************************************************************************//******************************************************************************** Function:     Interpret_JFIF_to_HTML** Description:  Generates html showing the JFIF information contained in*               a JFIF data array, as retrieved with get_JFIF** Parameters:   JFIF_array - a JFIF data array, as from get_JFIF*               filename - the name of the JPEG file being processed ( used*                          by the script which displays the JFIF thumbnail)*** Returns:      output - the HTML string*******************************************************************************/function Interpret_JFIF_to_HTML( $JFIF_array, $filename ){        $output = "";        if ( $JFIF_array !== FALSE )        {                $output .= "<H2 class=\"JFIF_Main_Heading\">Contains JPEG File Interchange Format (JFIF) Information</H2>\n";                $output .= "\n<table class=\"JFIF_Table\" border=1>\n";                $output .= "<tr class=\"JFIF_Table_Row\"><td class=\"JFIF_Caption_Cell\">JFIF version: </td><td class=\"JFIF_Value_Cell\">". sprintf( "%d.%02d", $JFIF_array['Version1'], $JFIF_array['Version2'] ) . "</td></tr>\n";                if ( $JFIF_array['Units'] == 0 )                {                        $output .= "<tr class=\"JFIF_Table_Row\"><td class=\"JFIF_Caption_Cell\">Pixel Aspect Ratio: </td><td class=\"JFIF_Value_Cell\">" . $JFIF_array['XDensity'] ." x " . $JFIF_array['YDensity'] . "</td></tr>\n";                }                elseif ( $JFIF_array['Units'] == 1 )                {                        $output .= "<tr class=\"JFIF_Table_Row\"><td class=\"JFIF_Caption_Cell\">Resolution: </td><td class=\"JFIF_Value_Cell\">" . $JFIF_array['XDensity'] ." x " . $JFIF_array['YDensity'] . " pixels per inch</td></tr>\n";                }                elseif ( $JFIF_array['Units'] == 2 )                {                        $output .= "<tr class=\"JFIF_Table_Row\"><td class=\"JFIF_Caption_Cell\">Resolution: </td><td class=\"JFIF_Value_Cell\">" . $JFIF_array['XDensity'] ." x " . $JFIF_array['YDensity'] . " pixels per cm</td></tr>\n";                }                $output .= "<tr class=\"JFIF_Table_Row\"><td class=\"JFIF_Caption_Cell\">JFIF (uncompressed) thumbnail: </td><td class=\"JFIF_Value_Cell\">";                if ( ( $JFIF_array['ThumbX'] != 0 ) && ( $JFIF_array['ThumbY'] != 0 ) )                {                        $output .= $JFIF_array['ThumbX'] ." x " . $JFIF_array['ThumbY'] . " pixels, Thumbnail Display Not Yet Implemented</td></tr>\n";                        // TODO Implement JFIF Thumbnail display                }                else                {                        $output .= "None</td></tr>\n";                }                $output .= "</table><br>\n";        }        return $output;}