thinkphp 上传bmp图片

最新推荐文章于 2023-05-19 16:02:02 发布
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最新推荐文章于 2023-05-19 16:02:02 发布
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分类专栏： PHP 文章标签： bmp thinkphp
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本文提供了两个PHP函数，用于从BMP格式读取图片并转换为GD库支持的格式，以及创建并输出BMP格式的图片。支持多种位深及压缩方式。
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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(legendsky@hotmail.com) 
	* @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 != '') 
	    { 
	        $fp = fopen("test.bmp", "wb"); 
	        fwrite($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; 
	}
把以上两个函数，放到thinkphp公用方法里即可，
公用方法路径：根目录/application\Common\Common/function.php。
转自：https://www.zhaokeli.com/Article/1817.html