Tiff Compression

[Kevin Goodwin]

Hello everyone; I have noticed when saving files in tiff format in Affinity photo I am not

given a choice about compression...you get LZW compression whether you want it or not

and oddly enough the compression increases the file size...most other editors I have used

allow you to turn off compression...I see no value in archiving files when compression is automatic

and usually with tiff files not much of an advantage...possibly a nuisance later on with printing.

Is there a way to export tiff files and avoid unnecessary compression? Thanks   Kevin Goodwin

[Fixx]

You can use some third party app to save tiff without compression. 

Generally LZW is very robust implementation and using it does almost never any harm.

[R C-R]

12 hours ago, Kevin Goodwin said:

you get LZW compression whether you want it or not

and oddly enough the compression increases the file size...

Increases compared to what?

[Kevin Goodwin]

Hello again....About tiff compression...LZW compression increases the export file size with16 bit per channel files.

In other words it does NOT WORK with 16 bit per channel files at all. It simply makes the file bigger which is strange. So

export with LZW compression and the 16 bit per channel tiff actually gets larger by a several MBs which is very odd. 

LZW compression of tiff files only works properly with 8 bits per channel files. So it is absolutely useless with

16 bit files...anyway every other program I have used gives you the export option of turning compression off.

 Thanks   Kevin Goodwin

[lepr]

.

[FxRphoto]

Hello everybody,

I have just noticed that the TIFF files are always LZW compressed, even when you open them uncompressed and then just hit command/S to save them.

It is indeed a big issue because we ought to have the choice regardless of wether or not it harms the files. 

Why the hell Affinity Photo is the only software not to offer that simple feature ?

Fx

As a post scriptum and To confirm (if necessary) what is said above :
my 36MB DNG file processed in Iridient Developer and saved uncompressed in 16bit TIFF is a file about 130MB. Opened in AP and just exported without any changes, it become an LZW compressed TIFF file about 137 MB. Not a lot, but still. And why using compression if it's not for saving space ?

Edited June 11, 2018 by FxRphoto

[Michael Naylor]

I'm amazed this problem still exists after all this time.  Wake up Affinity.

[Fixx]

It is a problem for few people. Normally it does not affect work flow and quality any way.

[FxRphoto]

4 minutes ago, Fixx said:

It is a problem for few people. Normally it does not affect work flow and quality any way.

Of course it does not affect neither the workflow or the quality. But the purpose of compression is to save space, not to increase it. 

For 16bits images LZW compression is not only useless but it produces files that are larger than uncompressed ones. And that's the point.
Having the choice to use it or not is a key feature, and I guess, not so difficult to implement.

A better choice would be to offer a ZIP compression with several degrees of compression (the best method to lossless compress 16bits files), but it is probably a more difficult feature to add.

Regarding the fact that it affects a few people, since it is not clearly displayed in Affinity Photo, the only way to see that a LZW compression is actually applied to all the files saved in TIFF, is to check the properties of the files. Not many do that, indeed. It took myself months to notice it. Not a reason to consider that it's not important. 

And, as a reminder, Affinity Photo is, to my knowledge, the only software not to have the choice of TIFF compression. 

Fx