(三) Image 类对bmp 格式图片处理 产生的问题

在使用框架自带的Image类 时候 , 会发现 bmp 格式的图片 不管的是处理还是缩略图都会报错 ,其实是少了2个方法, 这2个方法是

imagecreatefrombmp

imagebmp
这2个方法是网上找过的 ,但是发现有坑, 我自己修改了下, 经过测试是可以用的

/** * BMP 创建函数 * @author simon * @param string $filename path of bmp file * @example who use,who knows * @return resource of GD */function imagecreatefrombmp( $filename ){    if ( !$f1 = fopen( $filename, "rb" ) )        return FALSE;    $FILE = unpack( "vfile_type/Vfile_size/Vreserved/Vbitmap_offset", fread( $f1, 14 ) );    if ( $FILE['file_type'] != 19778 )        return FALSE;    $BMP = unpack( 'Vheader_size/Vwidth/Vheight/vplanes/vbits_per_pixel' . '/Vcompression/Vsize_bitmap/Vhoriz_resolution' . '/Vvert_resolution/Vcolors_used/Vcolors_important', fread( $f1, 40 ) );    $BMP['colors'] = pow( 2, $BMP['bits_per_pixel'] );    if ( $BMP['size_bitmap'] == 0 )        $BMP['size_bitmap'] = $FILE['file_size'] - $FILE['bitmap_offset'];    $BMP['bytes_per_pixel'] = $BMP['bits_per_pixel'] / 8;    $BMP['bytes_per_pixel2'] = ceil( $BMP['bytes_per_pixel'] );    $BMP['decal'] = ($BMP['width'] * $BMP['bytes_per_pixel'] / 4);    $BMP['decal'] -= floor( $BMP['width'] * $BMP['bytes_per_pixel'] / 4 );    $BMP['decal'] = 4 - (4 * $BMP['decal']);    if ( $BMP['decal'] == 4 )        $BMP['decal'] = 0;    $PALETTE = array();    if ( $BMP['colors'] < 16777216 ){        $PALETTE = unpack( 'V' . $BMP['colors'], fread( $f1, $BMP['colors'] * 4 ) );    }    $IMG = fread( $f1, $BMP['size_bitmap'] );    $VIDE = chr( 0 );    $res = imagecreatetruecolor( $BMP['width'], $BMP['height'] );    $P = 0;    $Y = $BMP['height'] - 1;    while( $Y >= 0 ){        $X = 0;        while( $X < $BMP['width'] ){            if ( $BMP['bits_per_pixel'] == 32 ){                $COLOR = unpack( "V", substr( $IMG, $P, 3 ) );                $B = ord(substr($IMG, $P,1));                $G = ord(substr($IMG, $P+1,1));                $R = ord(substr($IMG, $P+2,1));                $color = imagecolorexact( $res, $R, $G, $B );                if ( $color == -1 )                    $color = imagecolorallocate( $res, $R, $G, $B );                $COLOR[0] = $R*256*256+$G*256+$B;                $COLOR[1] = $color;            }elseif ( $BMP['bits_per_pixel'] == 24 )                $COLOR = unpack( "V", substr( $IMG, $P, 3 ) . $VIDE );            elseif ( $BMP['bits_per_pixel'] == 16 ){                $COLOR = unpack( "n", substr( $IMG, $P, 2 ) );                $COLOR[1] = $PALETTE[$COLOR[1] + 1];            }elseif ( $BMP['bits_per_pixel'] == 8 ){                $COLOR = unpack( "n", $VIDE . substr( $IMG, $P, 1 ) );                $COLOR[1] = $PALETTE[$COLOR[1] + 1];            }elseif ( $BMP['bits_per_pixel'] == 4 ){                $COLOR = unpack( "n", $VIDE . substr( $IMG, floor( $P ), 1 ) );                if ( ($P * 2) % 2 == 0 )                    $COLOR[1] = ($COLOR[1] >> 4);                else                    $COLOR[1] = ($COLOR[1] & 0x0F);                $COLOR[1] = $PALETTE[$COLOR[1] + 1];            }elseif ( $BMP['bits_per_pixel'] == 1 ){                $COLOR = unpack( "n", $VIDE . substr( $IMG, floor( $P ), 1 ) );                if ( ($P * 8) % 8 == 0 )                    $COLOR[1] = $COLOR[1] >> 7;                elseif ( ($P * 8) % 8 == 1 )                    $COLOR[1] = ($COLOR[1] & 0x40) >> 6;                elseif ( ($P * 8) % 8 == 2 )                    $COLOR[1] = ($COLOR[1] & 0x20) >> 5;                elseif ( ($P * 8) % 8 == 3 )                    $COLOR[1] = ($COLOR[1] & 0x10) >> 4;                elseif ( ($P * 8) % 8 == 4 )                    $COLOR[1] = ($COLOR[1] & 0x8) >> 3;                elseif ( ($P * 8) % 8 == 5 )                    $COLOR[1] = ($COLOR[1] & 0x4) >> 2;                elseif ( ($P * 8) % 8 == 6 )                    $COLOR[1] = ($COLOR[1] & 0x2) >> 1;                elseif ( ($P * 8) % 8 == 7 )                    $COLOR[1] = ($COLOR[1] & 0x1);                $COLOR[1] = $PALETTE[$COLOR[1] + 1];            }else                return FALSE;            imagesetpixel( $res, $X, $Y, $COLOR[1] );            $X++;            $P += $BMP['bytes_per_pixel'];        }        $Y--;        $P += $BMP['decal'];    }    fclose( $f1 );    return $res;}/** * 创建bmp格式图片 * * @author: legend([e-mail]) * @link: http://www.ugia.cn/?p=96 * @description: create Bitmap-File with GD library * @version: 0.1 * * @param resource $im          图像资源 * @param string   $filename    如果要另存为文件，请指定文件名，为空则直接在浏览器输出 * @param integer  $bit         图像质量(1、4、8、16、24、32位) * @param integer  $compression 压缩方式，0为不压缩，1使用RLE8压缩算法进行压缩 * * @return integer */function imagebmp($im, $filename = '', $bit = 8, $compression = 0){    if (!in_array($bit, array(1, 4, 8, 16, 24, 32)))    {        $bit = 8;    }    else if ($bit == 32) // todo:32 bit    {        $bit = 24;    }    $bits = pow(2, $bit);    // 调整调色板    imagetruecolortopalette($im, true, $bits);    $width  = imagesx($im);    $height = imagesy($im);    $colors_num = imagecolorstotal($im);    if ($bit <= 8)    {        // 颜色索引        $rgb_quad = '';        for ($i = 0; $i < $colors_num; $i ++)        {            $colors = imagecolorsforindex($im, $i);            $rgb_quad .= chr($colors['blue']) . chr($colors['green']) . chr($colors['red']) . "\0";        }        // 位图数据        $bmp_data = '';        // 非压缩        if ($compression == 0 || $bit < 8)        {            if (!in_array($bit, array(1, 4, 8)))            {                $bit = 8;            }            $compression = 0;            // 每行字节数必须为4的倍数，补齐。            $extra = '';            $padding = 4 - ceil($width / (8 / $bit)) % 4;            if ($padding % 4 != 0)            {                $extra = str_repeat("\0", $padding);            }            for ($j = $height - 1; $j >= 0; $j --)            {                $i = 0;                while ($i < $width)                {                    $bin = 0;                    $limit = $width - $i < 8 / $bit ? (8 / $bit - $width + $i) * $bit : 0;                    for ($k = 8 - $bit; $k >= $limit; $k -= $bit)                    {                        $index = imagecolorat($im, $i, $j);                        $bin |= $index << $k;                        $i ++;                    }                    $bmp_data .= chr($bin);                }                $bmp_data .= $extra;            }        }        // RLE8 压缩        else if ($compression == 1 && $bit == 8)        {            for ($j = $height - 1; $j >= 0; $j --)            {                $last_index = "\0";                $same_num   = 0;                for ($i = 0; $i <= $width; $i ++)                {                    $index = imagecolorat($im, $i, $j);                    if ($index !== $last_index || $same_num > 255)                    {                        if ($same_num != 0)                        {                            $bmp_data .= chr($same_num) . chr($last_index);                        }                        $last_index = $index;                        $same_num = 1;                    }                    else                    {                        $same_num ++;                    }                }                $bmp_data .= "\0\0";            }            $bmp_data .= "\0\1";        }        $size_quad = strlen($rgb_quad);        $size_data = strlen($bmp_data);    }    else    {        // 每行字节数必须为4的倍数，补齐。        $extra = '';        $padding = 4 - ($width * ($bit / 8)) % 4;        if ($padding % 4 != 0)        {            $extra = str_repeat("\0", $padding);        }        // 位图数据        $bmp_data = '';        for ($j = $height - 1; $j >= 0; $j --)        {            for ($i = 0; $i < $width; $i ++)            {                $index  = imagecolorat($im, $i, $j);                $colors = imagecolorsforindex($im, $index);                if ($bit == 16)                {                    $bin = 0 << $bit;                    $bin |= ($colors['red'] >> 3) << 10;                    $bin |= ($colors['green'] >> 3) << 5;                    $bin |= $colors['blue'] >> 3;                    $bmp_data .= pack("v", $bin);                }                else                {                    $bmp_data .= pack("c*", $colors['blue'], $colors['green'], $colors['red']);                }                // todo: 32bit;            }            $bmp_data .= $extra;        }        $size_quad = 0;        $size_data = strlen($bmp_data);        $colors_num = 0;    }    // 位图文件头    $file_header = "BM" . pack("V3", 54 + $size_quad + $size_data, 0, 54 + $size_quad);    // 位图信息头    $info_header = pack("V3v2V*", 0x28, $width, $height, 1, $bit, $compression, $size_data, 0, 0, $colors_num, 0);    // 写入文件    if ($filename != '')    {        $fp = fopen($filename, "wb");        fwrite($fp, $file_header);        fwrite($fp, $info_header);        fwrite($fp, $rgb_quad);        fwrite($fp, $bmp_data);        fclose($fp);        return 1;    }    // 浏览器输出    header("Content-Type: image/bmp");    echo $file_header . $info_header;    echo $rgb_quad;    echo $bmp_data;    return 1;}