Re: Re: how to detect type of image

On 28.04.2007 10:39, Tijnema ! wrote:

First of all, i don't see any reason why this works better then other functions, as it also relies on the magic bytes. Second, for your switch, you should use the constants (IMAGETYPE_GIF,IMAGETYPE_JPEG,...) instead of just using decimal values. Tijnema

Yes, I wrote this function because none of the others worked for me properly. I found functions which determined the file type by a given extension. Those file types can be easily faked by using an other extension. I wrote the function a long time ago and was using PHP 4. The IMAGETYPE constants are available since PHP 4.3.0.

It should, but instead try this: $image_size = getimagesize($filename); echo $image_size['mime'];

I needed a way to get the correct extension of an image file. It is possible to create an array with all MIME types and the matching extensions. Then you just have to search for $image_size['mime'] in it and you have correct extension. As I see there is a way, which is a lot easier: You can use $image_size[2] which is a flag indicating type of the image. 1 = GIF 2 = JPG 3 = PNG 4 = SWF, 5 = PSD 6 = BMP 7 = TIFF(intel byte order) 8 = TIFF(motorola byte order) 9 = JPC 10 = JP2 11 = JPX 12 = JB2 13 = SWC 14 = IFF 15 = WBMP 16 = XBM Since PHP 4.3.0 you can use constants. I reckon $type = exif_imagetype($filename); is the same as $image_size = getimagesize($filename); $type = $image_size[2]; exif_imagetype would have to be faster than getimagesize because it only gets the file type. getimagesize does also get the width/height, MIME type, etc. I think getimagesize depends on exif_imagetype and will work even if exif is disabled, but I am not sure. Tim