照片经照相机照出后，在未经一些图像处理软件处理的时候，我们可以通过照片来检测出一些有用的信息，比如时间，相机的品牌，相机的型号，光圈等等，这些信息我们叫EXIF信息。我们通常可以借助于一些软件来实现，比如acdsee，我们也可以用PHP程序来进行检测。代码如下：
<?
/**
* 获取图象信息的函数
*
* 一个全面获取图象信息EXIF的函数
*
* @access public
* @param string $img 图片路径
* @return array
*/
function GetImageInfoVal($ImageInfo,$val_arr) {
$InfoVal = "未知";
foreach($val_arr as $name=>$val) {
if ($name==$ImageInfo) {
$InfoVal = &$val;
break;
}
}
return $InfoVal;
}
function GetImageInfo($img) {
$imgtype = array("", "GIF", "JPG", "PNG", "SWF", "PSD", "BMP", "TIFF(intel byte order)", "TIFF(motorola byte order)", "JPC", "JP2", "JPX", "JB2", "SWC", "IFF", "WBMP", "XBM");
$Orientation = array("", "top left side", "top right side", "bottom right side", "bottom left side", "left side top", "right side top", "right side bottom", "left side bottom");
$ResolutionUnit = array("", "", "英寸", "厘米");
$YCbCrPositioning = array("", "the center of pixel array", "the datum point");
$ExposureProgram = array("未定义", "手动", "标准程序", "光圈先决", "快门先决", "景深先决", "运动模式", "肖像模式", "风景模式");
$MeteringMode_arr = array(
"0" => "未知",
"1" => "平均",
"2" => "中央重点平均测光",
"3" => "点测",
"4" => "分区",
"5" => "评估",
"6" => "局部",
"255" => "其他"
);
$Lightsource_arr = array(
"0" => "未知",
"1" => "日光",
"2" => "荧光灯",
"3" => "钨丝灯",
"10" => "闪光灯",
"17" => "标准灯光A",
"18" => "标准灯光B",
"19" => "标准灯光C",
"20" => "D55",
"21" => "D65",
"22" => "D75",
"255" => "其他"
);
$Flash_arr = array(
"0" => "flash did not fire",
"1" => "flash fired",
"5" => "flash fired but strobe return light not detected",
"7" => "flash fired and strobe return light detected",
);
$exif = exif_read_data ($img,"IFD0");
if ($exif===false) {
$new_img_info = array ("文件信息" => "没有图片EXIF信息");
}
else
{
$exif = exif_read_data ($img,0,true);
$new_img_info = array (
"文件信息" => "-----------------------------",
"文件名" => $exif[FILE][FileName],
"文件类型" => $imgtype[$exif[FILE][FileType]],
"文件格式" => $exif[FILE][MimeType],
"文件大小" => $exif[FILE][FileSize],
"时间戳" => date("Y-m-d H:i:s",$exif[FILE][FileDateTime]),
"图像信息" => "-----------------------------",
"图片说明" => $exif[IFD0][ImageDescription],
"制造商" => $exif[IFD0][Make],
"型号" => $exif[IFD0][Model],
"方向" => $Orientation[$exif[IFD0][Orientation]],
"水平分辨率" => $exif[IFD0][XResolution].$ResolutionUnit[$exif[IFD0][ResolutionUnit]],
"垂直分辨率" => $exif[IFD0][YResolution].$ResolutionUnit[$exif[IFD0][ResolutionUnit]],
"创建软件" => $exif[IFD0][Software],
"修改时间" => $exif[IFD0][DateTime],
"作者" => $exif[IFD0][Artist],
"YCbCr位置控制" => $YCbCrPositioning[$exif[IFD0][YCbCrPositioning]],
"版权" => $exif[IFD0][Copyright],
"摄影版权" => $exif[COMPUTED][Copyright.Photographer],
"编辑版权" => $exif[COMPUTED][Copyright.Editor],
"拍摄信息" => "-----------------------------",
"Exif版本" => $exif[EXIF][ExifVersion],
"FlashPix版本" => "Ver. ".number_format($exif[EXIF][FlashPixVersion]/100,2),
"拍摄时间" => $exif[EXIF][DateTimeOriginal],
"数字化时间" => $exif[EXIF][DateTimeDigitized],
"拍摄分辨率高" => $exif[COMPUTED][Height],
"拍摄分辨率宽" => $exif[COMPUTED][Width],
/*
The actual aperture value of lens when the image was taken.
Unit is APEX.
To convert this value to ordinary F-number(F-stop),
calculate this value's power of root 2 (=1.4142).
For example, if the ApertureValue is '5', F-number is pow(1.41425,5) = F5.6.
*/
"光圈" => $exif[EXIF][ApertureValue],
"快门速度" => $exif[EXIF][ShutterSpeedValue],
"快门光圈" => $exif[COMPUTED][ApertureFNumber],
"最大光圈值" => "F".$exif[EXIF][MaxApertureValue],
"曝光时间" => $exif[EXIF][ExposureTime],
"F-Number" => $exif[EXIF][FNumber],
"测光模式" => GetImageInfoVal($exif[EXIF][MeteringMode],$MeteringMode_arr),
"光源" => GetImageInfoVal($exif[EXIF][LightSource], $Lightsource_arr),
"闪光灯" => GetImageInfoVal($exif[EXIF][Flash], $Flash_arr),
"曝光模式" => ($exif[EXIF][ExposureMode]==1?"手动":"自动"),
"白平衡" => ($exif[EXIF][WhiteBalance]==1?"手动":"自动"),
"曝光程序" => $ExposureProgram[$exif[EXIF][ExposureProgram]],
/*
Brightness of taken subject, unit is APEX. To calculate Exposure(Ev) from BrigtnessValue(Bv), you must add SensitivityValue(Sv).
Ev=Bv+Sv Sv=log((ISOSpeedRating/3.125),2)
ISO100:Sv=5, ISO200:Sv=6, ISO400:Sv=7, ISO125:Sv=5.32.
*/
"曝光补偿" => $exif[EXIF][ExposureBiasValue]."EV",
"ISO感光度" => $exif[EXIF][ISOSpeedRatings],
"分量配置" => (bin2hex($exif[EXIF][ComponentsConfiguration])=="01020300"?"YCbCr":"RGB"),//'0x04,0x05,0x06,0x00'="RGB" '0x01,0x02,0x03,0x00'="YCbCr"
"图像压缩率" => $exif[EXIF][CompressedBitsPerPixel]."Bits/Pixel",
"对焦距离" => $exif[COMPUTED][FocusDistance]."m",
"焦距" => $exif[EXIF][FocalLength]."mm",
"等价35mm焦距" => $exif[EXIF][FocalLengthIn35mmFilm]."mm",
/*
Stores user comment. This tag allows to use two-byte character code or unicode. First 8 bytes describe the character code. 'JIS' is a Japanese character code (known as Kanji).
'0x41,0x53,0x43,0x49,0x49,0x00,0x00,0x00':ASCII
'0x4a,0x49,0x53,0x00,0x00,0x00,0x00,0x00':JIS
'0x55,0x4e,0x49,0x43,0x4f,0x44,0x45,0x00':Unicode
'0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00':Undefined
*/
"用户注释编码" => $exif[COMPUTED][UserCommentEncoding],
"用户注释" => $exif[COMPUTED][UserComment],
"色彩空间" => ($exif[EXIF][ColorSpace]==1?"sRGB":"Uncalibrated"),
"Exif图像宽度" => $exif[EXIF][ExifImageLength],
"Exif图像高度" => $exif[EXIF][ExifImageWidth],
"文件来源" => (bin2hex($exif[EXIF][FileSource])==0x03?"digital still camera":"unknown"),
"场景类型" => (bin2hex($exif[EXIF][SceneType])==0x01?"A directly photographed image":"unknown"),
"缩略图文件格式" => $exif[COMPUTED][Thumbnail.FileType],
"缩略图Mime格式" => $exif[COMPUTED][Thumbnail.MimeType]
);
}
return $new_img_info;
}
//Example
print_r(GetImageInfo("DSC00599.JPG"));
?>
更新时间：2010-5-29
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