'use strict';
var pngSignature = 'PNGrnx1an'; function isPNG (buffer) {
if (pngSignature === buffer.toString('ascii', 1, 8)) { if ('IHDR' !== buffer.toString('ascii', 12, 16)) { throw new TypeError('invalid png'); } return true; }
}
function calculate (buffer) {
return { 'width': buffer.readUInt32BE(16), 'height': buffer.readUInt32BE(20) };
}
module.exports = {
'detect': isPNG, 'calculate': calculate
};