How to find out if the jpg is invalid?

System_Failure

I am trying to code an uploader which would manipulate the uploaded images, and invalid jpg/jpeg files seem to be quite a big problem while manipulating.

I did some research, and the one method that I could find was in the manual, for imagecreate() function, but that requires a special library installed (net something I believe).

I am wondering, if there is any way I could do a check on the image (other than mime types, I believe they do the check with the extension, which can easily be changed) to see if this is really a valid jpg/jpeg or not.

Thanks in advance 🙂

Frederick

using filetype() will check for image/jpeg whether it is jpg, JPG, jpeg or JPEG

if (filetype($imagename) != "image/jpeg") {
Oh No
} else {
Oh Ya
}

tsinka

Hi,

according to the manual filetype returns only one of the values fifo, char, dir, block, link, file, and unknown.

I think getimagesize could be an alternative since it doesn't rely on the gd lib. getimagesize returns false if the image is an invalid image or corrupt. The function returns an array containing metadata such as size, type, mime string ....

To check if gd support is enabled just create a little phpinfo script and check the output for a "gd" section.

Thomas

System_Failure

Originally posted by tsinka
Hi,

according to the manual filetype returns only one of the values fifo, char, dir, block, link, file, and unknown.

I think getimagesize could be an alternative since it doesn't rely on the gd lib. getimagesize returns false if the image is an invalid image or corrupt. The function returns an array containing metadata such as size, type, mime string ....

To check if gd support is enabled just create a little phpinfo script and check the output for a "gd" section.

Thomas

Thats a great idea! Thanks a lot 🙂

move3rd

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