JPEGs not converting from TIFs

[Nigel Kendall]

Hi,

A strange thing is going on with JPEGs that have been converted from TIFs in Preview on an iMac. When I open them in Affinity Photo they still open as TIFs but still with a .JPEG extension.

What's going on here?

Nigel 

[Alfred]

Maybe I would understand immediately if I were a Mac user, but please explain what you mean by “they still open as TIFs”.

[Nigel Kendall]

Thanks for getting back.

When the tiff files are converted as a batch in Preview they are given a '.JPEG' extension, but when I open these files in AP they retain the .JPEG extension but save as tiffs with a .TIF extension, with no reduction in file size as one would expect. It's bizarre!

Occasionally I will try to save a .JPEG file but AP flags up 'This file type is unrecognised'. 

Go figure!

[GarryP]

I still don’t quite understand what you’re doing or what’s happening when you do it.

Can you share a sample image, after the “converted as a batch in Preview” step, and give us a step-by-step workflow telling us exactly how to reproduce the issue?

[Nigel Kendall]

Yes it is very complicated. I'm using AP on an iMac running OS Monterey. Here's a workflow:

1. Batch convert tiff files to jpeg in Review. Sample 'converted' file attached
2. Open 'converted' file (with .jpeg extension) in AP
3. File opens and I edit the image
4. I save the file in its jpeg format, but it saves with a .tif extension (or alternatively I get an alert 'This file format is not recognised'

I'm attaching a screen grab from my folder, which shows no difference in size between tiffs and jpegs of the same files. I've also attempted to upload an individual file but it would not post.

[markw]

Can you clarify exactly what steps you take when Saving your edited images in step 4?
I’ve just tried this (though not with the same number of files as in your screenshot. So a possible variable to consider?) and I’m not getting any unexpected results.
A screen recording could possibly be helpful so we can see exactly what happens.

[Nigel Kendall]

Hi,

In Step 4 I flatten the image and click save and it saves to the orginal folder, overwriting the original.

I'll have a go at recording the actions.

It's very odd. I've used photo editing software for over 30 years, professionally and in retirement, and never had this sort of thing happen.

[GaryLearnTech]

Looking at the data in your screenshot, I think the problem is happening at your step #1.  Your batch process is not converting the output files.  It's outputting copies of your tiff files but renaming them to look like JPEGs.  It's your initial batch conversion process that needs investigating.

Affinity Photo is correctly recognising the raw TIFF data, without alerting you to the underlying error (except where "Occasionally I will try to save a .JPEG file but AP flags up 'This file type is unrecognised'.")

[Nigel Kendall]

Yes I think this makes sense. Frankly, I would prefer to do the conversion in AP but I can't get the hang of batch processing simply to change file type. 

Any advice would be great! 

[markw]

20 hours ago, Nigel Kendall said:

I would prefer to do the conversion in AP but I can't get the hang of batch processing simply to change file type.

To use Photos Batch Job processor to do the converting;
Go to File > New Batch Job.
In the window that opens, on the Left Hand side add all the TIFF files you want to convert.
In the top section of the Right Hand side under ‘Output’ you can either Save to the same location as the originals or choose another location by selecting; Save into… and choosing a location by clicking the ellipsis icon to the right.
Next, deselect the default option of ‘Save as AFPhoto’ and select the “Save as” file option of your choice from those offered. Click on the ellipsis icon at the far right of your chosen file type to open a popup where you can set any other user definable output options like for example; the amount of file compression to be used, etc…
If you do not want to change the resulting files dimensions then leave the W & H fields empty.
If you want to run a Macro that you have in AP’s Macro library select and Apply it now.
If you don’t want to run any Macros then just ignore that section.
Now click the OK button bottom right corner of the window to start the process.