With the file extension ALV so-called Adobe Level files of the image editing software Photoshop are marked. Alv files contain adjustment values (histogram values) for the individual channels of the color space RGB (red, green, blue) of an opened image. In the German version they are called tone value correction files.
The dialog box can be reached via the menu item Image-> Adjustments-> Levels, in which also ALV files can be loaded and saved. This makes it easy to apply your own tonal adjustments to an image. Various, often used settings are already included in Photoshop, for example increase contrast, brighten shadows or darken Mitteltne.
Most often resolving problems with opening ALV files is very simple. Just install an appropriate program that supports such files. All of the listed programs support ALV files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of ALV files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate ALV files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Adobe Photoshop applications is not on the list, select "Browse" option in order to manually locate the directory where Adobe Photoshop has been installed.
Sometimes problems with opening ALV files may not lie with the application itself, but can arise due to other causes, such as: