말씀하신대로..

$thumb_path = $data_path.'/thumb';

를..

$thumb_path = $data_path.'/_thumb/170x150_90';

로 변경했구요..

불당썸은 bbs/_thumb/thumb.lib.php 에 저장되어 있습니다.

소스는..

===================================================================================
<?
// 원본 이미지를 넘기면 비율에 따라 썸네일 이미지를 생성함
// 가로, 세로, 파일경로, 생성경로, true
function createThumb($imgWidth, $imgHeight, $imgSource, $imgThumb='', $iscut=false)
{
    if (!$imgThumb)
        $imgThumb = $imgSource;

    $size = getimagesize($imgSource);

    if ($size[2] == 1)
        $source = imagecreatefromgif($imgSource);
    else if ($size[2] == 2)
        $source = imagecreatefromjpeg($imgSource);
    else if ($size[2] == 3)
        $source = imagecreatefrompng($imgSource);
    else
        continue;

    $rate = $imgWidth / $size[0];
    $height = (int)($size[1] * $rate);

    if ($height < $imgHeight) {

        $target = @imagecreatetruecolor($imgWidth, $height);

    } else {

        $target = @imagecreatetruecolor($imgWidth, $imgHeight);

    }

    @imagecopyresampled($target, $source, 0, 0, 0, 0, $imgWidth, $height, $size[0], $size[1]);
    @imagejpeg($target, $imgThumb, 100);
    @chmod($imgThumb, 0606); // 추후 삭제를 위하여 파일모드 변경
}

// 프로그램 : 불당썸 2.0.x
// 개 발 자 : 아빠불당 (http://www.kingsquare.nl/phppsdreader
*
*    TODO
*    ----
*    - read color values for "multichannel data" PSD files
*    - find and implement (hunter)lab to RGB algorithm
*    - fix 32 bit colors... has something to do with gamma and exposure available since CS2, but dunno how to read them...
*/


class PhpPsdReader {
    var $infoArray;
    var $fp;
    var $fileName;
    var $tempFileName;
    var $colorBytesLength;

    function PhpPsdReader($fileName) {
        set_time_limit(0);
        $this->infoArray = array();
        $this->fileName = $fileName;
        $this->fp = fopen($this->fileName,'r');

        if (fread($this->fp,4)=='8BPS') {
            $this->infoArray['version id'] = $this->_getInteger(2);
            fseek($this->fp,6,SEEK_CUR); // 6 bytes of 0's
            $this->infoArray['channels'] = $this->_getInteger(2);
            $this->infoArray['rows'] = $this->_getInteger(4);
            $this->infoArray['columns'] = $this->_getInteger(4);
            $this->infoArray['colorDepth'] = $this->_getInteger(2);
            $this->infoArray['colorMode'] = $this->_getInteger(2);


            /* COLOR MODE DATA SECTION */ //4bytes Length The length of the following color data.
            $this->infoArray['colorModeDataSectionLength'] = $this->_getInteger(4);
            fseek($this->fp,$this->infoArray['colorModeDataSectionLength'],SEEK_CUR); // ignore this snizzle

            /*  IMAGE RESOURCES */
            $this->infoArray['imageResourcesSectionLength'] = $this->_getInteger(4);
            fseek($this->fp,$this->infoArray['imageResourcesSectionLength'],SEEK_CUR); // ignore this snizzle

            /*  LAYER AND MASK */
            $this->infoArray['layerMaskDataSectionLength'] = $this->_getInteger(4);
            fseek($this->fp,$this->infoArray['layerMaskDataSectionLength'],SEEK_CUR); // ignore this snizzle


            /*  IMAGE DATA */
            $this->infoArray['compressionType'] = $this->_getInteger(2);
            $this->infoArray['oneColorChannelPixelBytes'] = $this->infoArray['colorDepth']/8;
            $this->colorBytesLength = $this->infoArray['rows']*$this->infoArray['columns']*$this->infoArray['oneColorChannelPixelBytes'];

            if ($this->infoArray['colorMode']==2) {
                $this->infoArray['error'] = 'images with indexed colours are not supported yet';
                return false;
            }
        } else {
            $this->infoArray['error'] = 'invalid or unsupported psd';
            return false;
        }
    }


    function getImage() {
        // decompress image data if required
        switch($this->infoArray['compressionType']) {
            // case 2:, case 3: zip not supported yet..
            case 1:
                // packed bits
                $this->infoArray['scanLinesByteCounts'] = array();
                for ($i=0; $i<($this->infoArray['rows']*$this->infoArray['channels']); $i++) $this->infoArray['scanLinesByteCounts'][] = $this->_getInteger(2);
                $this->tempFileName = tempnam(realpath('/tmp'),'decompressedImageData');
                $tfp = fopen($this->tempFileName,'wb');
                foreach ($this->infoArray['scanLinesByteCounts'] as $scanLinesByteCount) {
                    fwrite($tfp,$this->_getPackedBitsDecoded(fread($this->fp,$scanLinesByteCount)));
                }
                fclose($tfp);
                fclose($this->fp);
                $this->fp = fopen($this->tempFileName,'r');
            default:
                // continue with current file handle;
                break;
        }

        // let's write pixel by pixel....
        $image = imagecreatetruecolor($this->infoArray['columns'],$this->infoArray['rows']);

        for ($rowPointer = 0; ($rowPointer < $this->infoArray['rows']); $rowPointer++) {
            for ($columnPointer = 0; ($columnPointer < $this->infoArray['columns']); $columnPointer++) {
                /*    The color mode of the file. Supported values are: Bitmap=0;
                    Grayscale=1; Indexed=2; RGB=3; CMYK=4; Multichannel=7;
                    Duotone=8; Lab=9.
                */
                switch ($this->infoArray['colorMode']) {
                    case 2: // indexed... info should be able to extract from color mode data section. not implemented yet, so is grayscale
                        exit;
                        break;
                    case 0:
                        // bit by bit
                        if ($columnPointer == 0) $bitPointer = 0;
                        if ($bitPointer==0) $currentByteBits = str_pad(base_convert(bin2hex(fread($this->fp,1)), 16, 2),8,'0',STR_PAD_LEFT);
                        $r = $g = $b = (($currentByteBits[$bitPointer]=='1')?0:255);
                        $bitPointer++;
                        if ($bitPointer==8) $bitPointer = 0;
                        break;

                    case 1:
                    case 8: // 8 is indexed with 1 color..., so grayscale
                        $r = $g = $b = $this->_getInteger($this->infoArray['oneColorChannelPixelBytes']);
                        break;

                    case 4: // CMYK
                        $c = $this->_getInteger($this->infoArray['oneColorChannelPixelBytes']);
                        $currentPointerPos = ftell($this->fp);
                        fseek($this->fp,$this->colorBytesLength-1,SEEK_CUR);
                        $m = $this->_getInteger($this->infoArray['oneColorChannelPixelBytes']);
                        fseek($this->fp,$this->colorBytesLength-1,SEEK_CUR);
                        $y = $this->_getInteger($this->infoArray['oneColorChannelPixelBytes']);
                        fseek($this->fp,$this->colorBytesLength-1,SEEK_CUR);
                        $k = $this->_getInteger($this->infoArray['oneColorChannelPixelBytes']);
                        fseek($this->fp,$currentPointerPos);
                        $r = round(($c * $k) / (pow(2,$this->infoArray['colorDepth'])-1));
                        $g = round(($m * $k) / (pow(2,$this->infoArray['colorDepth'])-1));
                        $b = round(($y * $k) / (pow(2,$this->infoArray['colorDepth'])-1));

                          break;

                          case 9: // hunter Lab
                              // i still need an understandable lab2rgb convert algorithm... if you have one, please let me know!
                            $l = $this->_getInteger($this->infoArray['oneColorChannelPixelBytes']);
                            $currentPointerPos = ftell($this->fp);
                            fseek($this->fp,$this->colorBytesLength-1,SEEK_CUR);
                            $a = $this->_getInteger($this->infoArray['oneColorChannelPixelBytes']);
                            fseek($this->fp,$this->colorBytesLength-1,SEEK_CUR);
                            $b =  $this->_getInteger($this->infoArray['oneColorChannelPixelBytes']);
                            fseek($this->fp,$currentPointerPos);

                            $r = $l;
                            $g = $a;
                            $b = $b;

                        break;
                    default:
                        $r = $this->_getInteger($this->infoArray['oneColorChannelPixelBytes']);
                        $currentPointerPos = ftell($this->fp);
                        fseek($this->fp,$this->colorBytesLength-1,SEEK_CUR);
                        $g = $this->_getInteger($this->infoArray['oneColorChannelPixelBytes']);
                        fseek($this->fp,$this->colorBytesLength-1,SEEK_CUR);
                        $b =  $this->_getInteger($this->infoArray['oneColorChannelPixelBytes']);
                        fseek($this->fp,$currentPointerPos);
                        break;

                }

                if (($this->infoArray['oneColorChannelPixelBytes']==2)) {
                    $r = $r >> 8;
                    $g = $g >> 8;
                    $b = $b >> 8;
                } elseif (($this->infoArray['oneColorChannelPixelBytes']==4)) {
                    $r = $r >> 24;
                    $g = $g >> 24;
                    $b = $b >> 24;
                }

                $pixelColor = imagecolorallocate($image,$r,$g,$b);
                imagesetpixel($image,$columnPointer,$rowPointer,$pixelColor);
            }
        }
        fclose($this->fp);
        if (isset($this->tempFileName)) unlink($this->tempFileName);
        return $image;
    }

    /**
    *
    * PRIVATE FUNCTIONS
    *
    */

    function _getPackedBitsDecoded($string) {
        /*
        The PackBits algorithm will precede a block of data with a one byte header n, where n is interpreted as follows:
        n Meaning
        0 to 127 Copy the next n + 1 symbols verbatim
        -127 to -1 Repeat the next symbol 1 - n times
        -128 Do nothing

        Decoding:
        Step 1. Read the block header (n).
        Step 2. If the header is an EOF exit.
        Step 3. If n is non-negative, copy the next n + 1 symbols to the output stream and go to step 1.
        Step 4. If n is negative, write 1 - n copies of the next symbol to the output stream and go to step 1.

        */

        $stringPointer = 0;
        $returnString = '';

        while (1) {
            if (isset($string[$stringPointer])) $headerByteValue = $this->_unsignedToSigned(hexdec(bin2hex($string[$stringPointer])),1);
            else return $returnString;
            $stringPointer++;

            if ($headerByteValue >= 0) {
                for ($i=0; $i <= $headerByteValue; $i++) {
                    $returnString .= $string[$stringPointer];
                    $stringPointer++;
                }
            } else {
                if ($headerByteValue != -128) {
                    $copyByte = $string[$stringPointer];
                    $stringPointer++;

                    for ($i=0; $i < (1-$headerByteValue); $i++) {
                        $returnString .= $copyByte;
                    }
                }
            }
        }
    }

    function _unsignedToSigned($int,$byteSize=1) {
        switch($byteSize) {
            case 1:
                if ($int<128) return $int;
                else return -256+$int;
                break;

            case 2:
                if ($int<32768) return $int;
                else return -65536+$int;

            case 4:
                if ($int<2147483648) return $int;
                else return -4294967296+$int;

            default:
                return $int;
        }
    }

    function _hexReverse($hex) {
        $output = '';
        if (strlen($hex)%2) return false;
        for ($pointer = strlen($hex);$pointer>=0;$pointer-=2) $output .= substr($hex,$pointer,2);
        return $output;
    }

    function _getInteger($byteCount=1) {
        switch ($byteCount) {
            case 4:
                // for some strange reason this is still broken...
                return @reset(unpack('N',fread($this->fp,4)));
                break;

            case 2:
                return @reset(unpack('n',fread($this->fp,2)));
                break;

            default:
                return hexdec($this->_hexReverse(bin2hex(fread($this->fp,$byteCount))));
        }
    }
}

/**
 * Returns an image identifier representing the image obtained from the given filename, using only GD, returns an empty string on failure
 *
 * @param string $fileName
 * @return image identifier
 */

function imagecreatefrompsd($fileName) {
    $psdReader = new PhpPsdReader($fileName);
    if (isset($psdReader->infoArray['error'])) return '';
    else return $psdReader->getImage();
}
?>

===================================================================================

입니다..