Files sizes reduced on import

To make sure the real reason for the confusion is understood reread this part of Larry's post:

including auto rotation a JPEG is made and placed in the preview folder - a preview is also created for each RAW photo imported

The screenshot you posted showed a portrait oriented photo which had an autorotate tag attached to it by the camera. This tells iPhoto to create a rotated version and save it in the Preview folder. It will contain a level of jpeg compression applied during the rotation and file creation process resulting in a smaller file size.

There is a way to avoid that but it requries several additional steps to get the file into the library.

OT

Thanks, Terence Devlin, your User Tip article was informative, even if some of it was beyond my current level of understanding.

Perhaps my (and maybe ScotteWilson's) concerns could be better understood by backing up a bit. This was how iPhoto '09 worked from my standpoint:

1) I had a JPEG image on my camera which my camera info tells me was roughly 5 MB in size.

2) I hooked up the camera to the Mac and imported the image directly into iPhoto '09.

3) I did some editing to the image (not cropping) and then dragged and dropped it to the desktop for later use. (It could be for e-mailing, uploading to FB or SmugMug, putting in a non-iPhoto related folder, etc.)

4) I clicked on the "Get Info" for the desktop icon of this image, and it showed me that the desktop version of this now-edited image is still 5 MB (actually, at least a few KB more than the original on the camera due to the editing).

5) When I e-mailed the desktop image as an attachment, as long as I selected "Actual Size", the size of the attached image was still 5+ MB. Uploads to SmugMug also showed me the same 5+ filesize for the image.

Regardless of what iPhoto '09 may have been doing behind the scenes, the APPARENT result for me was that my image never lost data -- and by that, I'm only talking about image quality -- through all of these simple means of importing and exporting. It was wonderfully "Apple" in its simplicity, really, how I could drag-and-drop to and from iPhoto and then sling around the image willy-nilly into different apps and uploading sites and not worry about the image quality being changed. (Again, that is what seemed to be happening on the surface, but it was convincing enough to me.)

So ... I finally upgrade to iPhoto '11, and my tried-and-true simple method doesn't work anymore, or it sometimes does and sometimes doesn't, but it shouldn't at all based on my understanding of your article. Now, I should be choosing the "Export" function and have a good understanding of what each of the options ("Original", "Current", etc.) are going to do, or not do, to my image. And none of them appear to be able to give me what I really want -- see above.

Which brings me to your remark:

Well that is the point of exporting the Original...

I'm sure it was a "Well, duh" moment for you, lol, and perhaps rightfully so from your standpoint. But it actually took me some time to figure out why I would ever even NEED the option to export original images. Then it occurred to me that, from time to time, there have been JPEG images in my iPhoto library that I didn't feel the need to manipulate/edit and probably exported anyway.

But please understand that, in several years of using '09, my method meant that I NEVER had to distinguish between exporting original, unedited images vs. ones that had been edited -- it was all done collectively through the same easy process. For instance, if an Event folder had a mixture of edited and unedited images, I could just drag-and-drop the entire Event to the desktop, and a new desktop folder would be created with those images inside, looking the same as they did in iPhoto and with the expected file sizes. And ready to rock on for other uses.

Now, in iPhoto '11, it would seem that I need to either export the non-edited images separately as "Originals" so that they retain their original filesizes, or I treat all of the images as a batch and put up with the originals being altered through the exporting process in whatever way the edited images would be. Either way ... a bit of a bummer.

Okay, so you now know where I've been, so to speak, and what I was expecting but not experiencing in iPhoto '11. Obviously, having too many different options for exporting is not my cup of tea, lol, especially since I can't find the one that consistently replicates what '09 seemed to be doing.

I would greatly welcome suggestions about how I can get closest to my desired export simplicity/capability in iPhoto '11.

WHat is it that you want? A large file? A certain Pixel dimension? The size of the FIle that holds the photo is not directly controlable and is of litte to no importance - what is important is the content of that file and in photos bigger is not necessarly better -- if you just want a large file for some reason then export the photo with maximum quality and the file will be larger that the original file - or for an even bigger file export it as a TIFF - then it will be even bigger

What is it that you want?

LN

I had a JPEG image on my camera which my camera info tells me was roughly 5 MB in size.

No you didn't. You had a photograph on your camera. That photograph was stored in a file that was compressed and that, when compressed, came to 5MB. First thing to get a handle on here is

That Jpeg is not your Photograph. It's a container for your photo. It has as much in common with your photo as the shoe box does for the shoes - it's a handy, compact way of moving it around.

Second thing to get a handle on" Jpeg is not an image format. It's a compression format - like zip and so on. It's attuned for image data, sure, but it's actually a compression format. When you view a photo that's stored in a jpeg it's decompressed so you see it.

3) I did some editing to the image (not cropping) and then dragged and dropped it to the desktop for later use.

I see you keep saying that you're "not cropping" as though this is of some relevance. It has very little relevance to the ultimate file size of the jepg.

4) I clicked on the "Get Info" for the desktop icon of this image, and it showed me that the desktop version of this now-edited image is still 5 MB (actually, at least a few KB more than the original on the camera due to the editing).

Fluke that the file size turned out the same or similar. Why? Because it's not the same file. It's a whole new file with the photograph in it.

This is what happens when you edit the photo. It's unstuffed for you to look at it. You look. You make your changes. The changes are stored in the database - literally, recorded in the tables within the db. There are no changes made to your Photo at all. What you see as changes are iPhoto calculating the results of your decisions and showing them to you. To get the photo out of iPhoto with the edits, it creates a new image and puts that into a new file, and as the file is a jpeg, it's compressed. The level of compression applied - by fluke - happens in this case to be similar to what your camera applies. It could apply more or less, but that's all.

When I e-mailed the desktop image as an attachment, as long as I selected "Actual Size", the size of the attached image was still 5+ MB.

'Actual Size' has very very little to do with MB, KB or whatever. Actual Size refers to the dimensions of the Photos - length by breadth - measured in pixels.

So, to make this clear: you can export a photo at 'Actual Size' that is (using your numbers here) 5MB, or a lot less, or a lot larger. Because the file size is all about the amount of compression applied.

Regardless of what iPhoto '09 may have been doing behind the scenes, the APPARENT result for me was that my image never lost data -- and by that, I'm only talking about image quality -- through all of these simple means of importing and exporting.

Hmm, but the 5mb measurement has nothing to do with "data", and nothing to do with "image quality". You can get a very good image off a 1mb or a 10 MB file - and viewed online you'd have significant difficulty telling them apart. You can have the same amount of data in a 1mb file as a 10mb, only in the 1mb file it's squeezed a whole lot more.

Where file size is important with Jpegs is if you are thinking of subsequent editing of the image in a standard, lossy editor. Because every time you edit a Jpeg (which remember, iPhoto doesn't do) there is dataloss as the file is recompressed.

So, all of this is by way of saying that there is no image qality loss, no dataloss, just a different amount of compression used in the file.

Bear with me, LarryHN, I'm not a "photo guy", neither on the camera end or the computer end. It's iPhone or point-and-shoot cameras, relatively simple editing through iPhoto, distribution through various means, and that's about as far as I take things. Consequently, a lot of photo-related jargon goes over my head. Now you know who you are dealing with, lol.

But I suppose maybe I am talking about pixel dimensions? I CAN tell that if I take a picture of an object three times but have the camera image quality setting set to, say, 1 megapixel, 4 megapixels, and 8 megapixels respectively (all of the other camera settings being the same), the resulting size of the file increases each time. And I know that the 1 megapixel version is going to be less useful to me than the 8 megapixel one in terms of using as a clear desktop background on a 24" iMac or if I need to crop away a large part of the image but still have enough high quality image left for printing.

So, for demonstration's sake, let's say I'm used to a 9 megapixel, "superfine" camera setting, and that I download the images to the computer that typically result in 4 MB JPEG files. It's simplistic, I know, but for me, 4 MB is kind of the telltale number for these files. In iPhoto '09, if I did some editing (but not cropping) to these images and then dragged them to the desktop, I could accurately predict that the resulting desktop images would have roughly the same filesize as the originals, leading me to have the PERCEPTION (hey, I'll own that it may be all it is) that the quality of the image had not changed. So, if I yanked one of those photos into a mail message and send it off to my wife, I knew that she was going to get the same quality image on her end, as long as I chose "Actual Size".

Enter my iPhoto '11 experience ... in which the dragging-to-the-desktop method of "exporting" created, unknown to me at the time, a 600KB-ish version of a JPEG image that I know good and well had an original filesize of 2.7 MB. (The only editing I had done to the image in iPhoto was to add brightness.) When I sent it on to my wife, she was unable to use it as a desktop background image because it wasn't "clear", but she was able to use the 2.7 MB unedited version just fine. (I worked around iPhoto to send that one to her.)

Ergo, from my perspective, file size and image quality are quite related, whatever the technical truth of the matter is.

So, in answer to your "What is it that you want?" question: if I import a X megapixel, "superfine" JPEG image that has a filesize of Y into iPhoto '11 -- and that's the image quality (and, dare I say it, filesize) that I find particularly useful for my purposes -- I want the same thing to come out on the export end, plus whatever edits I've done. And I want it to be easy, like it was in '09.

You need to read TD post and study compression - these if NO corrolation between photos quality ane file size - if you only change one parameter (pixel dimension for example) them higher qualiy (larger pixel dimensions) does create a larger file

But when you import, edit and export you are changing many parameters

Exporting a TIFF produces a much, much large file and has no effect on photo quality

What you are seeing is primarilly differnt compression which changes file size

Once again what exactly is your goal? A giant file (export a TIFF) or a quality photo?

If you goal is a 5 MB file then you will have to experiment with settings to fine one that gives you one you like

LN

In iPhoto '09, if I did some editing (but not cropping) to these images and then dragged them to the desktop, I could accurately predict that the resulting desktop images would have roughly the same filesize as the originals,

And that's what's not true. You couldn't 'accurately predict' that, it was a coincidence. There is no reason why a 600kb file would be any less clear than a 2.7mb one when used as a deskop background. None at all. But there would lots of reasons if you sent her a file that was reduced in dimension - length by breadth.

For instance go here

http://terrydev.smugmug.com/Travel/2008/Spain-08-Girona-Barcelona/5876203_8BW6Fn #!i=365047689&k=RqcznSX

and note the first image of the storefront. Not the most exciting photo you'll ever see, but from a quality persepctive, perfectly fine. Drag it to the desktop. It's 94kb. So, what's the connection between image quality and file size again?

Well, TD, your image looks pretty good when viewed on the SmugMug site, although best when viewed as a small preview and less so as a large. I dragged it to my desktop, where, as you said, it created a 94kb image file. Then I right-clicked on it and selected "Set Desktop Picture" ... and it looks terrible. As in poor-resolution terrible, because every line and letter has choppy, pixelated edges. Clearly, bigger is not better when viewing this image. I'm guessing that it wouldn't make a very good 8x10 print either. For me, then ... useless.

So I'm not sure how this proved the point you were trying to make.

My objective has been to produce edited images for myself and others that have a high enough resolution (w/o necessarily having huge file sizes) so that they look crisp and clear as desktop backgrounds or as prints as large as 8x10, should one choose to use them for such. (Clear on that now, LarryHN? I don't give a rat's *** to how big the file size is as long as it meets this objective.)

For whatever reason, it has been my experience that JPEG-compressed images that had filesizes greater than 2MB tended to work pretty well for my needs, and ones that were less than 1MB (like your 94kb storefront), not so much. Yes, yes, I can hear you and LarryHN shouting again that file size has nothing to at all to do with it and that it has been a total coincidence. I'm sure you're right. Whatever. But I'm guessing that the file that you used to make that nice 11x14 print of that storefront that's hanging in your bedroom is a lot bigger than 94kb, lol.

Through blind luck and sheer ignorance apparently, I had been achieving my ends very successfully in iPhoto '09 through my drag-and-drop means of exporting, which required no expertise in the science/technology of image compression. But something has changed about the way this works in iPhoto '11. And I just wanted to know how to get back there again in the simplest possible fashion. That's was it. That was why I posted. And quite frankly, that's why my initial post was directed to ScotteWilson, because I wanted to see if another person of more modest understanding and similar concerns had been able to translate your rather tech-y replies into long-term success.

I think we've firmly established that you and LarryHN are very well learned in this field and that I am something of a moron in it. And while I appreciate your collective attempts to educate me, I don't think that you are able to talk "down" to me in the manner that I obviously need right now. When I have a lot more time on my hands, perhaps I'll try to become more learned about it too so that I will know what the really important points are.

I am finished with this thread now, so please don't feel the need to reply, because I will not be checking back.

OK - Have a nice day

LN

Well you didn't start this conversation, you don't decide when it ends.

Then I right-clicked on it and selected "Set Desktop Picture" ... and it looks terrible. As in poor-resolution terrible, because every line and letter has choppy, pixelated edges.

And that illustrates my point precisely. The reason it looks poor is because of the dimensions of the image - you're stretching a 450 x 600 pixel image over a large (what size?) desktop. It has nothing to do with the file size.

Regards

TD