What is a TIFF with layers?

[BeauRX]

I enhanced a scanned document (TIFF) with a couple layers and inadvertently selected save rather than export and was presented with the dialog below. I know some about TIFFs related to scanning and being a common lossless format but not having layers. Wondering if anyone know the meaning, is this just stored as a separate image for each layer modification? Also is there some value, or application to this format?

[Fixx]

If you want to save over old TIFF you have to flatten the layers. If you have layers in document you can save as affinityphoto file, or export to TIFF (layers merged in process), and the there is this: it is possible to export with Affinity layers. Seems you can also save over old TIFF if you include layers.

Now your question: Affinity saved TIFF with layers contain Affinity proprietary information (layers). There should be also a composite image included which is readable by other software. Layers are readible only by Affinity, there is no other use for them but you can open and continue editing layered TIFF later. I do not think that is a very good workflow.

[Old Bruce]

16 minutes ago, BeauRX said:

Also is there some value, or application to this format?

Depends on the type of enhancement you did. If you are not happy with it in two days/weeks time and want to refine the adjustment/enhancements you can open the tiff with Affinity Layers in Photo (not PhotoShop, Draw, Paintshop, etc...) to continue refining. The file size will be smaller than an Affinity Photo document.

[iconoclast]

Tiff supports layers and the Alpha channel for transparencies. Theoretical! But as far as I know, it depends on the application with which you exported the Tiff and the one you want to load it with. For example, I made the experience in the past, that Tiffs with transparencies, I created with GIMP, lost their transparencies if I opened it in Photoshop. Possibly the same vice versa. Moreover GIMP had a bug concerning Tiffs, that made them useless and difficult to delete from disc, if they contain transparencies.

And while Photoshop supports layers in Tiffs sionce many years, GIMP does it since about a year ago or so.

I'm not sure about if Affinity Photo fully supports Tiffs that are written in other programs, especially Photoshop. If there are layers that are no pixel layers, it might be vectors (for example a clipping path) and/or text layers. But as far as I know, Photo will not support the text layers as editable text.

This is all without warranty.

[Old Bruce]

1 minute ago, Fixx said:

I do not think that is a very good workflow.

I knew I forgot something. I agree, it is a bad way to work. Better to save as .afphoto

[BeauRX]

Thanks for all the info. I figured a common flat image format and afphoto were sufficient but good to know. Also seems less confusing to have clear separation of edit/app environment data and presentation/sharing of data. Thx

 

[iconoclast]

Generally it is a good idea to use the .afphoto format to save documents in Photo you are working on (like it is to save them as PSD in Photoshop), because you can save layers, selections, guidelines, vectors and other things with it. Other file types don't support that. For certain needs you should choose the export formats. For professional printing TIFF is the most reliable choice. But layers doesn't make sense for printing. For lossless compression use the LZW-Algorithm in Tiffs. For the web you should choose JPEG or PNG (PNG also supports transparencies, JPEG doesn't). JPEG also is a good format to archive images. But its compression method isn't lossless. So you shouldn't compress too much and/or too often.

[Old Bruce]

To iconoclast's excellent summation I would add only another caveat for JPEG is that JPEGs will create artifacts in the image.

[iconoclast]

1 minute ago, Old Bruce said:

To iconoclast's excellent summation I would add only another caveat for JPEG is that JPEGs will create artifacts in the image.

Yes, but that depends on the grade of compression. The quality you get depends on the adjustments you do in the export panel: Quality (Compression) slider and Resampling).

[walt.farrell]

2 hours ago, iconoclast said:

I'm not sure about if Affinity Photo fully supports Tiffs that are written in other programs, especially Photoshop.

A Photoshop TIFF saved with layers basically contains (if I understand it properly) a flat TIFF image, and a PSD file. To the extent that Photo understands PSD files, it also understands a TIFF file with the embedded PSD.

An Affinity TIFF with layers is basically the same concept: the file contains a flat TIFF image, and an Affinity native file, but only Affinity understands the embedded file.