//
|
// fast-image-size - Simple stand alone module to just extract the image size from image file without using special image libraries.
|
//
|
// Please refer to README.md for this module's documentations.
|
//
|
// NOTE:
|
// - Before changing this code please refer to the 'hacking the code section' on README.md.
|
//
|
// Copyright (c) 2013 Ziv Barber;
|
//
|
// Permission is hereby granted, free of charge, to any person obtaining
|
// a copy of this software and associated documentation files (the
|
// 'Software'), to deal in the Software without restriction, including
|
// without limitation the rights to use, copy, modify, merge, publish,
|
// distribute, sublicense, and/or sell copies of the Software, and to
|
// permit persons to whom the Software is furnished to do so, subject to
|
// the following conditions:
|
//
|
// The above copyright notice and this permission notice shall be
|
// included in all copies or substantial portions of the Software.
|
//
|
// THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
|
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
|
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
|
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
|
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
|
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
//
|
|
var fast_image_size_info = require('./package.json');
|
var fs = require('fs');
|
|
module.exports = exports = function ( file_path, callback ) {
|
// Internal options:
|
if ( file_path == '@version@' ) {
|
return fast_image_size_info.version;
|
} // Endif.
|
|
function getJpgSize( buffer_data, retInfo ) {
|
// Skip 5 chars, they are for signature
|
buffer_data = buffer_data.slice( 4 );
|
|
var i, next;
|
while (buffer_data.length) {
|
// read length of the next block
|
i = buffer_data.readUInt16BE( 0 );
|
|
// 0xFFC0 is baseline(SOF)
|
// 0xFFC2 is progressive(SOF2)
|
next = buffer_data[ i + 1 ];
|
if (next === 0xC0 || next === 0xC2) {
|
return {
|
'height' : buffer_data.readUInt16BE( i + 5 ),
|
'width' : buffer_data.readUInt16BE( i + 7 )
|
};
|
}
|
|
// move to the next block
|
buffer_data = buffer_data.slice( i + 2 );
|
}
|
}
|
|
function parseHeaderData ( buffer_data, callback_data ) {
|
var retInfo = {};
|
|
// Detect GIF:
|
if ( buffer_data[0] == 0x47 && buffer_data[1] == 0x49 && buffer_data[2] == 0x46 ) {
|
retInfo.type = 'gif';
|
retInfo.width = (buffer_data[7] * 256) + buffer_data[6];
|
retInfo.height = (buffer_data[9] * 256) + buffer_data[8];
|
|
// Detect JPEG:
|
} else if ( buffer_data[0] == 0xFF && buffer_data[1] == 0xD8 && buffer_data[2] == 0xFF && buffer_data[3] == 0xE0 ) {
|
retInfo.type = 'jpeg';
|
var size = getJpgSize( buffer_data, retInfo );
|
retInfo.width = size.width;
|
retInfo.height = size.height;
|
|
// Detect PNG:
|
} else if ( buffer_data[0] == 137 && buffer_data[1] == 80 && buffer_data[2] == 78 && buffer_data[3] == 71 && buffer_data[4] == 13 && buffer_data[5] == 10 && buffer_data[6] == 26 && buffer_data[7] == 10 ) {
|
retInfo.type = 'png';
|
|
if ( buffer_data[12] == 0x49 && buffer_data[13] == 0x48 && buffer_data[14] == 0x44 && buffer_data[15] == 0x52 ) {
|
retInfo.width = (buffer_data[16] * 256 * 256 * 256) + (buffer_data[17] * 256 * 256) + (buffer_data[18] * 256) + buffer_data[19];
|
retInfo.height = (buffer_data[20] * 256 * 256 * 256) + (buffer_data[21] * 256 * 256) + (buffer_data[22] * 256) + buffer_data[23];
|
} // Endif.
|
|
// Detect BMP:
|
} else if ( buffer_data[0] == 0x42 && buffer_data[1] == 0x4D ) {
|
retInfo.type = 'bmp';
|
retInfo.width = (buffer_data[21] * 256 * 256 * 256) + (buffer_data[20] * 256 * 256) + (buffer_data[19] * 256) + buffer_data[18];
|
retInfo.height = (buffer_data[25] * 256 * 256 * 256) + (buffer_data[24] * 256 * 256) + (buffer_data[23] * 256) + buffer_data[22];
|
} // Endif.
|
|
retInfo.image = file_path;
|
if ( !retInfo.type ) {
|
retInfo.type = 'unknown';
|
} // Endif.
|
|
if ( callback_data ) {
|
callback_data ( retInfo );
|
} // Endif.
|
|
return retInfo;
|
};
|
|
// Async mode:
|
if ( callback ) {
|
fs.exists ( file_path, function( exists ) {
|
if ( exists ) {
|
fs.open ( file_path, "r", function ( error, fd ) {
|
var bufferSize = fs.fstatSync( fd ).size;
|
var buffer = new Buffer( bufferSize );
|
fs.read ( fd, buffer, 0, bufferSize, null, function ( error, bytesRead, buffer ) {
|
fs.close ( fd );
|
parseHeaderData ( buffer, callback );
|
});
|
});
|
} else {
|
throw 'Error: Invalid file name.';
|
} // Endif.
|
});
|
|
// Sync mode:
|
} else {
|
var fd = fs.openSync ( file_path, "r" );
|
var bufferSize = fs.fstatSync( fd ).size;
|
var buffer = new Buffer( bufferSize );
|
var bytesRead = fs.readSync ( fd, buffer, 0, bufferSize, 0 );
|
fs.closeSync ( fd );
|
return parseHeaderData ( buffer, null );
|
} // Endif.
|
};
|
