Hacking Full-size Camera Panoramas to Work in Facebook: Page 3 of 5
Why Did This Work?
Unfortunately I had to crop way more of the image than I'm happy about doing. So now to figure out why this one worked. Is it the aspect ratio? File size? Final megapixel count? Once we know that, and can maximize the amount of image shown, then we can go back through the steps and see if any of these were unnecessary, hopefully resulting in the least amount of changes needed to get a pano to load.
6 Let's crop a little wider
The previous image, which finally worked, was cropped a lot. That's no bueno, so I'll try cropping less. It also down-scaled quite a bit, so I lost considerable resolution from the original file. The previous crop was 13,632 × 3,082, which is a 4.423:1 crop ratio. I'll try a 5:1 ratio next, and if that works, keep going up. For now I'll also scale the vertical height to 3,082 as well, so we're only changing one thing at a time.
5:1 CROP RESULT: It worked! Excellent… on to a wider crop then.
7 But first, a sanity test; crop the original!
Uh-oh… what if all that mattered was the crop ratio? Man I'm gonna be p***… quick, take the original file and crop it 5:1!
RESULT: Didn't work… I'm somewhat relieved, honestly ;-)
8 Now a second-sanity test; to scale
We're here already, so let's also scale the previous file to the 3,082 known-working height we saw before, which puts this 5:1 cropped image at a height of 15,410 pixels.
RESULT: Nope, that isn't it either. OK good, this whole post isn't in vain! Alrighty then, back to where we left off.
9 Let's keep cropping wider
Picking up where the ratio tests left off, previously we cropped the metadata-adjusted and filename-changed image to a 5:1 ratio and scaled to 3,082 high. Now let's try 6:1 and 3,082 height, which puts the width at 18,492.
6:1 CROP RESULT: No joy. OK, so at this point the acceptable aspect ratio appears to be between 5:1 and 6:1.
10 Let's find a maximum ratio
Keep in mind that the widest aspect ratio of my iPhone-created test files was 4.423:1, so even at 5:1 we are wider than the iPhone was giving us. For each test below, I'll continue to scale the vertical dimension to 3,082.
5.5:1 CROP RESULT: Yep!
5.7:1 CROP RESULT: That worked too!
5.9:1 CROP RESULT: Nope! OK, we've exceeded a limit
5.8:1 CROP RESULT: No again. I wonder if it's 5.75 then…
5.75:1 CROP RESULT: That worked too! OK, so it seems our maximum ratio is 5.75:1 (maybe there's another decimal we can go… if you want to know that, knock yourself out ;-)
11 Now let's see what I didn't need to do
Now I'll back up and see what didn't need to be done, from steps one to three. That means I'll go back to the original file, and just do the crop and scale, and see if that works — no partial or full EXIF change, and no name change.
RESULT: No go — which somewhat justifies what I'm doing here ;-)
12 Let's change the name first
Previously I did metadata changes first, but changing the file name is obviously easier. So I'll duplicate file 11 and change the name to IMG_9999.JPG
RESULT: Still no.
13 Camera make & model
Now I'll duplicate file 11 again (with original filename) and change metadata on that, again starting with the easy data; camera make and model
14 Camera make or model
Do I need to change both of these fields? Going back to a dupe of file 11 again, let's find out…
Make = Apple only RESULT: Not enough of a change.
Model = iPhone only RESULT: Not enough either!
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