jpeg.php

CMS系统 提供学习研究修改最好了 比流行的一些CMS简单 但是更容易理解 是帮助你学习PHPCMS系统的好东东哦

        }
        else
        {
                // No COM segment found
                return FALSE;
        }
}

/******************************************************************************
* End of Function:     get_jpeg_Comment
******************************************************************************/


/******************************************************************************
*
* Function:     put_jpeg_Comment
*
* Description:  Creates a new JPEG Comment segment from a string, 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 Comment segment will be put
*               $new_Comment - a string containing the new Comment
*
* Returns:      jpeg_header_data - the JPEG header data array with the new
*                                  JPEG Comment segment added
*
******************************************************************************/

function put_jpeg_Comment( $jpeg_header_data, $new_Comment )
{
        //Cycle through the header segments
        for( $i = 0; $i < count( $jpeg_header_data ); $i++ )
        {
                // If we find an COM header,
                if ( strcmp ( $jpeg_header_data[$i]['SegName'], "COM" ) == 0 )
                {
                        // Found a preexisting Comment block - Replace it with the new one and return.
                        $jpeg_header_data[$i]['SegData'] = $new_Comment;
                        return $jpeg_header_data;
                }
        }



        // No preexisting Comment block found, find where to put it by searching for the highest app segment
        $i = 0;
        while ( ( $i < count( $jpeg_header_data ) ) && ( $jpeg_header_data[$i]["SegType"] >= 0xE0 ) )
        {
                $i++;
        }


        // insert a Comment segment new at the position found of the header data.
        array_splice($jpeg_header_data, $i , 0, array( array(   "SegType" => 0xFE,
                                                                "SegName" => $GLOBALS[ "JPEG_Segment_Names" ][ 0xFE ],
                                                                "SegDesc" => $GLOBALS[ "JPEG_Segment_Descriptions" ][ 0xFE ],
                                                                "SegData" => $new_Comment ) ) );
        return $jpeg_header_data;
}

/******************************************************************************
* End of Function:     put_jpeg_Comment
******************************************************************************/




/******************************************************************************
*
* Function:     Interpret_Comment_to_HTML
*
* Description:  Generates html showing the contents of any JPEG Comment segment
*
* Parameters:   jpeg_header_data - the JPEG header data, as retrieved
*                                  from the get_jpeg_header_data function
*
* Returns:      output - the HTML
*
******************************************************************************/

function Interpret_Comment_to_HTML( $jpeg_header_data )
{
        // Create a string to receive the output
        $output = "";

        // read the comment segment
        $comment = get_jpeg_Comment( $jpeg_header_data );

        // Check if the comment segment was valid
        if ( $comment !== FALSE )
        {
                // Comment exists - add it to the output
                $output .= "<h2 class=\"JPEG_Comment_Main_Heading\">JPEG Comment</h2>\n";
                $output .= "<p class=\"JPEG_Comment_Text\">$comment</p>\n";
        }

        // Return the result
        return $output;
}

/******************************************************************************
* End of Function:     Interpret_Comment_to_HTML
******************************************************************************/




/******************************************************************************
*
* Function:     get_jpeg_intrinsic_values
*
* Description:  Retreives information about the intrinsic characteristics of the
*               jpeg image, such as Bits per Component, Height and Width.
*
* Parameters:   jpeg_header_data - the JPEG header data, as retrieved
*                                  from the get_jpeg_header_data function
*
* Returns:      array - An array containing the intrinsic JPEG values
*               FALSE - if the comment segment couldnt be found
*
******************************************************************************/

function get_jpeg_intrinsic_values( $jpeg_header_data )
{
        // Create a blank array for the output
        $Outputarray = array( );

        //Cycle through the header segments until Start Of Frame (SOF) is found or we run out of segments
        $i = 0;
        while ( ( $i < count( $jpeg_header_data) )  && ( substr( $jpeg_header_data[$i]['SegName'], 0, 3 ) != "SOF" ) )
        {
                $i++;
        }

        // Check if a SOF segment has been found
        if ( substr( $jpeg_header_data[$i]['SegName'], 0, 3 ) == "SOF" )
        {
                // SOF segment was found, extract the information

                $data = $jpeg_header_data[$i]['SegData'];

                // First byte is Bits per component
                $Outputarray['Bits per Component'] = ord( $data{0} );

                // Second and third bytes are Image Height
                $Outputarray['Image Height'] = ord( $data{ 1 } ) * 256 + ord( $data{ 2 } );

                // Forth and fifth bytes are Image Width
                $Outputarray['Image Width'] = ord( $data{ 3 } ) * 256 + ord( $data{ 4 } );

                // Sixth byte is number of components
                $numcomponents = ord( $data{ 5 } );

                // Following this is a table containing information about the components
                for( $i = 0; $i < $numcomponents; $i++ )
                {
                        $Outputarray['Components'][] = array (  'Component Identifier' => ord( $data{ 6 + $i * 3 } ),
                                                                'Horizontal Sampling Factor' => ( ord( $data{ 7 + $i * 3 } ) & 0xF0 ) / 16,
                                                                'Vertical Sampling Factor' => ( ord( $data{ 7 + $i * 3 } ) & 0x0F ),
                                                                'Quantization table destination selector' => ord( $data{ 8 + $i * 3 } ) );
                }
        }
        else
        {
                // Couldn't find Start Of Frame segment, hence can't retrieve info
                return FALSE;
        }

        return $Outputarray;
}


/******************************************************************************
* End of Function:     get_jpeg_intrinsic_values
******************************************************************************/





/******************************************************************************
*
* Function:     Interpret_intrinsic_values_to_HTML
*
* Description:  Generates html showing some of the intrinsic JPEG values which
*               were retrieved with the get_jpeg_intrinsic_values function
*
* Parameters:   values - the JPEG intrinsic values, as read from get_jpeg_intrinsic_values
*
* Returns:      OutputStr - A string containing the HTML
*
******************************************************************************/

function Interpret_intrinsic_values_to_HTML( $values )
{
        // Check values are valid
        if ( $values != FALSE )
        {
                // Write Heading
                $OutputStr = "<h2 class=\"JPEG_Intrinsic_Main_Heading\">Intrinsic JPEG Information</h2>\n";

                // Create Table
                $OutputStr .= "<table class=\"JPEG_Intrinsic_Table\" border=1>\n";

                // Put image height and width into table
                $OutputStr .= "<tr class=\"JPEG_Intrinsic_Table_Row\"><td class=\"JPEG_Intrinsic_Caption_Cell\">Image Height</td><td class=\"JPEG_Intrinsic_Value_Cell\">" . $values['Image Height'] . " pixels</td></tr>\n";
                $OutputStr .= "<tr class=\"JPEG_Intrinsic_Table_Row\"><td class=\"JPEG_Intrinsic_Caption_Cell\">Image Width</td><td class=\"JPEG_Intrinsic_Value_Cell\">" . $values['Image Width'] . " pixels</td></tr>\n";

                // Put colour depth into table
                if ( count( $values['Components'] ) == 1 )
                {
                        $OutputStr .= "<tr class=\"JPEG_Intrinsic_Table_Row\"><td class=\"JPEG_Intrinsic_Caption_Cell\">Colour Depth</td><td class=\"JPEG_Intrinsic_Value_Cell\">" . $values['Bits per Component'] . " bit Monochrome</td></tr>\n";
                }
                else
                {
                        $OutputStr .= "<tr class=\"JPEG_Intrinsic_Table_Row\"><td class=\"JPEG_Intrinsic_Caption_Cell\">Colour Depth</td><td class=\"JPEG_Intrinsic_Value_Cell\">" . ($values['Bits per Component'] * count( $values['Components'] ) ) . " bit</td></tr>\n";
                }

                // Close Table
                $OutputStr .= "</table>\n";

                // Return html
                return $OutputStr;
        }
}

/******************************************************************************
* End of Function:     Interpret_intrinsic_values_to_HTML
******************************************************************************/







/******************************************************************************
*
* Function:     get_jpeg_image_data
*
* Description:  Retrieves the compressed image data part of the JPEG file
*
* Parameters:   filename - the filename of the JPEG file to read
*
* Returns:      compressed_data - A string containing the compressed data
*               FALSE - if retrieval failed
*
******************************************************************************/

function get_jpeg_image_data( $filename )
{

        // prevent refresh from aborting file operations and hosing file
        ignore_user_abort(true);

        // Attempt to open the jpeg file
        $filehnd = @fopen($filename, 'rb');

        // Check if the file opened successfully
        if ( ! $filehnd  )
        {
                // Could't open the file - exit
                return FALSE;
        }


        // Read the first two characters
        $data = network_safe_fread( $filehnd, 2 );

        // Check that the first two characters are 0xFF 0xDA  (SOI - Start of image)
        if ( $data != "\xFF\xD8" )
        {
                // No SOI (FF D8) at start of file - close file and return;
                fclose($filehnd);
                return FALSE;
        }



        // Read the third character
        $data = network_safe_fread( $filehnd, 2 );

        // Check that the third character is 0xFF (Start of first segment header)
        if ( $data{0} != "\xFF" )
        {
                // NO FF found - close file and return
                fclose($filehnd);
                return;
        }

        // Flag that we havent yet hit the compressed image data
        $hit_compressed_image_data = FALSE;


        // Cycle through the file until, one of: 1) an EOI (End of image) marker is hit,
        //                                       2) we have hit the compressed image data (no more headers are allowed after data)
        //                                       3) or end of file is hit

        while ( ( $data{1} != "\xD9" ) && (! $hit_compressed_image_data) && ( ! feof( $filehnd ) ))
        {
                // Found a segment to look at.
                // Check that the segment marker is not a Restart marker - restart markers don't have size or data after them
                if (  ( ord($data{1}) < 0xD0 ) || ( ord($data{1}) > 0xD7 ) )
                {
                        // Segment isn't a Restart marker
                        // Read the next two bytes (size)
                        $sizestr = network_safe_fread( $filehnd, 2 );

                        // convert the size bytes to an integer
                        $decodedsize = unpack ("nsize", $sizestr);

                         // Read the segment data with length indicated by the previously read size
                        $segdata = network_safe_fread( $filehnd, $decodedsize['size'] - 2 );
                }

                // If this is a SOS (Start Of Scan) segment, then there is no more header data - the compressed image data follows
                if ( $data{1} == "\xDA" )
                {
                        // Flag that we have hit the compressed image data - exit loop after reading the data
                        $hit_compressed_image_data = TRUE;

                        // read the rest of the file in
                        // Can't use the filesize function to work out