Image hosting procedures: the short story

We offer image hosting in the galleries to all of our members. Please review these simple procedures to host your images in your topics.

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rjlittlefield
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Re: Image hosting procedures: the short story

Post by rjlittlefield »

Lou Jost wrote:
Thu Jul 09, 2020 12:01 pm
Rik, I tried to upload an image 259kb, 1000x952px, but I get an error flag saying the image is too big. Did so again here in this thread, with the same result.
Lou, I found one discussion that says
The .jpg image can contain the original dimensions in the EXIF data. When a file is edited the software may not alter it. phpBB is reading the EXIF data instead of determining the the actual dimensions of the image. Saving as .png or .gif will strip the EXIF data. If you "save for web" or specifically remove the EXIF data in the .jpg the issue goes away.
What was the workflow for generating your image? Can you check specifically what the EXIF says? Something like "exiftool -a -u -g1 foo.jpg" should get all the tags

--Rik

Lou Jost
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Re: Image hosting procedures: the short story

Post by Lou Jost »

Will do Rik, thanks. For what it's worth, I had no trouble uploading a similar-sized file to a PM this morning.

Edit- Just saw your second message. I shrunk it from a larger image. However, as I mentioned, the server did list the correct size, right next to the error flag saying it was too big.

Lou Jost
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Re: Image hosting procedures: the short story

Post by Lou Jost »

Image has been sent, Rik.

rjlnorm
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Re: Image hosting procedures: the short story

Post by rjlnorm »

Lou -- problem fixed, it seems. Please re-try the upload yourself.

_1110463.jpg

I found and removed a "feature" in the standard phpBB distribution, that was apparently "resizing" images to plupload quality 85%, even if the pixel count and file length were already within limits. This had a plethora of possible side effects, including altering image quality and color profile. I'm guessing it was the cause of the color profile oddness discussed HERE.

I have now tested several image files and observed that the file uploaded and the file subsequently downloaded are binary-equal. It's a bit humbling to think that I must not have run that test before.

I have also added this mod to the tidy little procedure of only 46 steps, in my notes for doing the upgrade to phpBB 3. But almost certainly that count is too small, since I'm pretty sure I have failed to record some steps, and I rather doubt that the process is done yet.

Please let me know whatever else you notice that is odd.

--Rik

Edit: resizing seems to be done on client side by plupload, versus server side by imagemagick. Or maybe it's done either place, depending on browser capabilities. This stuff is all too complicated for me to quickly understand in any detail.
Last edited by rjlnorm on Thu Jul 09, 2020 5:35 pm, edited 1 time in total.

Lou Jost
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Re: Image hosting procedures: the short story

Post by Lou Jost »

It worked for me now in the original trhead. Thanks for fixing it!

rjlittlefield
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Re: Image hosting procedures: the short story

Post by rjlittlefield »

Excellent. Thanks for calling my attention to this problem.

--Rik

Billy B
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Re: Image hosting procedures: the short story

Post by Billy B »

I'm new to the forum and would like to post a few photos, however after processing a photo through Export in PS and re-sizing it to 1024x 674, the KB is almost 600 KB and not the 300 you mention in the beginning of your post. Any suggestion's ? Great site with a lot of helpful photographers'....

rjlittlefield
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Re: Image hosting procedures: the short story

Post by rjlittlefield »

Billy B wrote:
Thu Jul 23, 2020 7:04 pm
after processing a photo through Export in PS and re-sizing it to 1024x 674, the KB is almost 600 KB and not the 300 you mention in the beginning of your post. Any suggestion's ?
In the current Photoshop, the best menu entry is File > Export > Save for Web (Legacy).

In the dialog that pops up, near the upper right corner there is a "Quality" field, which contains a number ranging from 0 to 100. Near the lower left corner of the same dialog, just underneath the image panel, there are a couple of lines of text that give the estimated file length and transfer time. I have outlined those here:

ExportDialog.jpg

The trick is to adjust the quality number so as to make the length number be a little under 300K. A simple way to do that is to highlight the number in the Quality field, then press the up-arrow or down-arrow keys to adjust the Quality number, while watching the number for file length. When you finally get length to be the right value, then click the Save button. It's always best to check the actual length as shown by an operating system file browser, since Photoshop's number is a little off sometimes.

--Rik

Billy B
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Re: Image hosting procedures: the short story

Post by Billy B »

Thank you Rik. I'll let you know how it works.

Chris S.
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Re: Image hosting procedures: the short story

Post by Chris S. »

rjlittlefield wrote:
Sat Jun 20, 2020 11:51 pm
. . . (To determine the URL of an image that is attached to another post, use your browser's function to "Open image in new tab" or its equivalent (the exact name varies between browsers), then copy the URL from that new browser tab. It will be something like "https://www.photomacrography.net/forum/download/file.php?id=123"
In Firefox, and easy way to get the URL of an image in another post is to right-click on the image, choose "View image info", and copy the text displayed to the right of "Location:".

--Chris S.

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