Feature suggestion: Content-based format detection

[Simon Brown]

While file extensions provide a quick and cheap way to identify the format of a file, it can sometimes be deceiving, such as in cases where the user has mistakenly given a file the wrong extension. As Paint.NET must read files anyway to open them, it seems logical to me to, instead of reading the extensions in the path of the file, to enumerate each FileType, reading a new method which would read the file's signature and return an enumeration dictating how likely it is that it is the correct FileType to read it the most extensively.

This would provide the following benefits:

• [*:1ju81x8w]If a user renames a file by accident or mistakenly gives it an extension when saving Paint.NET could still read it.
  [*:1ju81x8w]If a new format was released that was simply the same format given a new extension, a new FileType wouldn't be needed to read it.
  [*:1ju81x8w]There would be no problem with two FileTypes wanting the same extension.
  [*:1ju81x8w]FileTypes could read extensions of old formats already handled by Paint.NET that use the same extension (e.g. APNG).

If this feature causes problems with performance and the UI of open dialogs, then an alternative could be to simply use it as a tie-break and for unknown extensions.

Just my 20p.

[Simon Brown]

While file extensions provide a quick and cheap way to identify the format of a file, it can sometimes be deceiving, such as in cases where the user has mistakenly given a file the wrong extension. As Paint.NET must read files anyway to open them, it seems logical to me to, instead of reading the extensions in the path of the file, to enumerate each FileType, reading a new method which would read the file's signature and return an enumeration dictating how likely it is that it is the correct FileType to read it the most extensively.

This would provide the following benefits:

• [*:1ju81x8w]If a user renames a file by accident or mistakenly gives it an extension when saving Paint.NET could still read it.
  [*:1ju81x8w]If a new format was released that was simply the same format given a new extension, a new FileType wouldn't be needed to read it.
  [*:1ju81x8w]There would be no problem with two FileTypes wanting the same extension.
  [*:1ju81x8w]FileTypes could read extensions of old formats already handled by Paint.NET that use the same extension (e.g. APNG).

If this feature causes problems with performance and the UI of open dialogs, then an alternative could be to simply use it as a tie-break and for unknown extensions.

Just my 20p.

[Simon Brown]

While file extensions provide a quick and cheap way to identify the format of a file, it can sometimes be deceiving, such as in cases where the user has mistakenly given a file the wrong extension. As Paint.NET must read files anyway to open them, it seems logical to me to, instead of reading the extensions in the path of the file, to enumerate each FileType, reading a new method which would read the file's signature and return an enumeration dictating how likely it is that it is the correct FileType to read it the most extensively.

This would provide the following benefits:

• [*:1ju81x8w]If a user renames a file by accident or mistakenly gives it an extension when saving Paint.NET could still read it.
  [*:1ju81x8w]If a new format was released that was simply the same format given a new extension, a new FileType wouldn't be needed to read it.
  [*:1ju81x8w]There would be no problem with two FileTypes wanting the same extension.
  [*:1ju81x8w]FileTypes could read extensions of old formats already handled by Paint.NET that use the same extension (e.g. APNG).

If this feature causes problems with performance and the UI of open dialogs, then an alternative could be to simply use it as a tie-break and for unknown extensions.

Just my 20p.