FAQ: How big can files in the gallery be?

[Mike]

?

Rick is there some kind of limit imposed on file upload sizes?

[Rick]

Yes. There are limits on the sizes of files uploaded to the gallery.

The maximum file size is 8 MiB.

Image files can be jpg, png or gif, up to 3200 pixels square. (Note the absence of bmp format!)

Movie files can be wmv, avi or mov.

Audio files can be mp3 or ogg (but I can't see much use for them unless someone starts doing radio astronomy).

Raw data files can be txt, rtf, pdf, fits, raw, or tiff.

Restrictions can be changed. How big is the file in question?

[Rick]

There's an additional problem with images (but not raw data files). The images need to have a thumbnail, and if they're over a certain size, an intermediate image as well. With images over a certain size, one or both of these steps may fail. I think (but can't yet prove) that's because PowWeb's using an old old version of ImageMagick which seems to have some in-built limit. I've not been able to find out exactly what the limit is, but I have established that it's under 4 million pixels (because 1999x1999 fails), somewhere between 2300x1718 (which works) and 2300x1793 (which doesn't), at least for Robert's greyscale image...

[Rick]

I've given ImageMagick the heave-ho and switched to GD 2.x for the time being. This may introduce other problems, but at least it seems to work with bigger images than ImageMagick...

[Simon E]

Rick,
How did you get your avator to Read "Sometimes I wonder why I bother..."
Was there a website that coverts your txt to the image.
Simon

[Ian]

Si, see here.

http://forum.orpington-astronomy.org.uk/index.php?topic=5025.0

I'll append your post to that thread shortly...

[Rick]

Was there a website that coverts your txt to the image.

Oh, there are plenty of websites which will produce QRs, but I just installed qrencode. My icon changes with the weather, phase of the Moon, or climate, depending...

[JohnDeathridge]

Hi all I must be doing something wrong because i am reducing my file ize to 1.8mb and it keeps saying below -
The size of file you have uploaded is too large (maximum allowed is 6400 x 6400)!

Any advice much appreciated because I do not want to lose the resolution of the imnage. I have no problem at all on Astrobin...
 

[Rick]

I was able to upload a 2.4MB image without any trouble, so it's not (just) the file size causing trouble. There must be something else going on that's getting in the way.

Please could you email me (rick at orpington-astronomy dot org dot uk) the troublesome image, and I'll see if I can figure out what's happening.

[Rick]

Not figured out what might be causing this yet. No obvious error messages in the logs. Anyone else having problems?

[Carole]

Not me

[Rick]

John sent me his image, and the first thing I did was ask my system to tell me something about it:

Code Select Expand

Iris.jpeg: JPEG image data, JFIF standard 1.01, resolution (DPI), density 72x72, segment length 16, baseline, precision 8, 10000x6389, components 3

File name    : Iris.jpeg
File size    : 1946820 bytes
File date    : 2023:07:19 12:58:07
Resolution   : 10000 x 6389
JPEG Quality : 69

John's image was 10000 by 6389 pixels, and something in the gallery system was hitting the limits. During upload it has to create a thumbnail and a "normal size" image, and to do that it needs to de-compress the image. Apparently a colour image 10000 by 6389 is too big, but one half that size (5000 by 3195) is OK. I'm not sure exactly where the breaking point is, but as a 4K-UHDTV monitor is 4096 by 2160 (or therabouts) there's not much point in making images bigger than that for sharing online.

The flip side, and what caused me confusion, is that John's image had been JPEG-compressed to 69% quality. I usually avoid anything below 90% unless I'm really not bothered by appearances, and sometimes go up above 95% for photographs where detail's important. Obviously, for images that might be used in further processing I won't be using a lossy compression like JPEG at all, but that's another story...