How to get exposure values(aperture and exposure time) of pictures?

[slovintern]

I need to get exposure values of pictures and I would like to access this from the metadata. Is there a way to do this? If not is there a way to store this data while the camera is takes pictures in a matrix?

[rolfk]

I'm not aware of a standard LabVIEW library to do that (and it would get complicated to do as there are many different metadata formats for the different picture types). However I'm aware of this library which is a very thorough Java library to extract metadata from many different image formats. If I had to get metadata from a specific image format I would take this Java library and reimplement the specific format in LabVIEW.

[BRennhofer]

Hi

You can use this ActiveX solution:

http://www.x360soft.com/products/exifviewer/

For the forumpost (http://forums.ni.com/t5/Machine-Vision/Extract-metadata-from-jpg-date-picture-taken/m-p/870898#M2225... it helped.

best regards

Bernhard

[slovintern]

Hello, thak you for the reply

My supervisor wants me to do this using only labview. THe program is supposed to take pictures every 10 minutes and then multiply the luminance with the exposure values. If it cannot be extracted from the picture, can this information be saved in an array when the pictures are taken.

[BRennhofer]

try this link

http://forums.ni.com/t5/LabVIEW/Has-anyone-used-LabVIEW-to-read-Exif-information-from-an-image/td-p/...

there are good .net example who can extract Matadata from file.

[slovintern]

hm so i had a problem because the pictures did not have the values stored as metadata. is there a way to store them during runtime?

[BRennhofer]

how do you make your pictures? with which type of camera and which format do you use?

You need a format as explained in the following link .

http://en.wikipedia.org/wiki/Exchangeable_image_file_format

[slovintern]

I am using this right now but I don't have any values for exposure.