Advice For An Idle Thought

Thanks for that info, Lilfont. I should probably save the info from this thread somewhere. I'm not too tech savvy so I don't know anything about png or .rtf files, but I'm sure one of my kids knows!

 

One thing to watch out for... although it hasn't happened to me yet, I've read that it's not uncommon for memory sticks to fail. So it's probably a good idea to have multiple sources of backup.

 

My nephew says that he doesn't trust anything, so he has photos backed up on discs and a memory stick. Sort of a redundancy thing in case one or two things fail. Good point, Pat!

 

Great point. If you search for Memory Stick Fail you will find the reasons why. The main thing is that these are tiny electronic devices, and yes electronics do fail, but can be repaired. But the main reason is that folks treat them like a disc or LP record, and just toss them in a dirty drawer with a bunch of loose paper clips and chocolate chip cookie crumbs. Or store them in a damp or hot environment, like a box out in the garage. You wouldn't expect a transistor radio or cheep watch was damaged by such treatment.

There is also online file storage, as an option for back up. The problem with disc storage is the size of the files you will want to keep if the intention was to preserve the image.

 

You don't need to know much, here is all you need to know:

An .rtf file (Rich Text Format) is a simple form of text file. Many programs produce .rtf files when you write, the most famous might be WordPad. But I wrote .rtf, because you may have a favorite word processing program you use. It doesn't really matter which one you chose, or what kind of file it produces, it's just that .rtf files can be read across many platforms, like pc and apple.

A .png file (Portable Network Graphics) is like a .jpg file (JPEG). You will notice that the majority of images or photos on your computer are .jpg files (the name ends in .jpg) This form of image file is 'compressed' and deteriorates with each usage or transfer from one computer or program to the next. We have all seen the pixelation, or fuzzy square dots that some images have around the edges of text or parts of the image. This is the deterioration showing.

A png file, is an image file that is called lossless. There is no deterioration between uses. There are many lossless files, I choose this one as an example because it is used across many platforms and programs.

Hope that explains it.

 

It just occurred to me that the storage problem will just become worse since most people take photos today using digital cameras. This might be a good idea for a creative entrepreneur to come up with some useful, assuming there aren't ones I don't know about that already exist.

 

Thanks for the explanation, Lil. Very clear.

 

Jpeg images are only degraded when they're modified in an editor and resaved. Copying them from one system or storage device to another, or opening and closing them without saving, doesn't change their quality.

Here's a good summary article about the issue...

http://www.michaelfurtman.com/jpeg_myths.htm

 

Without going into great detail (I wrote "deteriorates with each usage or transfer from one computer or program to the next.")

The "myth" that the author of the linked article debunks, is that the jpg will deteriorate each time it's opened and closed. I didn't say that myth was true. Because you can open a jpg on your computer, or even open it without transferring it from one program to another.

The article is specifically written about the photoshop program. But there are many other programs besides image editors that all have the same general effect on a jpg when you process them, whether they are an image editor or a data storage transfer.

As the author tested, he was unable to see a deterioration until 15 such transfers. I can't speak for how much of a loss could be expected for any particular program or transfer of data.

If you wish to preserve a scan of your photos without loss, you will use a lossless file like png. If you are unconcerned about loss or very careful with the image transfer (transferring from your computer to the disc (1x) then back from the disc to a different or the same computer (1x) and then to an image processing program or printer (1x) presents 3 transfers out of the 15 the author experienced, I believe. I agree, if you made a high resolution scan, that loss would be negligible (3x), for most purposes. While the image is stored on the device, there will be no loss, only when it is downloaded back to a computer.

-1 upload to storage device (disc or stick)
-2 download to computer
-3 Print out on printer or edit in editor and print.
-4 save the edited jpg on your computer
-5 upload the saved jpg to the printer to print again.

The original image on the storage device will still be near pristine (-1) and a fresh copy can be down-loaded (-2) at any time and again and again.

I have never heard of a way to transfer a jpg without this loss. Uploading from your computer to the internet, then downloading back to your computer would represent two transfers, depending on what the computer on the internet did with it.

 

That wasn't my understanding of what the author said, so I went and reread the article. Is this the part you were referring to?

"I also tried “SAVE AS” multiple times. By the fifteenth time, image degradation was apparent. But judicial use of this method of saving (one or two times) results in no discernible loss."

In my experience, "save as" is always something you do from inside an image or file editing program after opening up a file. It's not the same as transferring a file from one system or storage device to another.

 

Right. But it depends on the program and how and where it saves or retrieves from. I am unsure of the program this author used. he wrote this in 2005 about Photoshop. Some programs may have their own temporary files (in which case I might assume there would be no loss).

When he 'Saved As' the file, he may have been saving it to his computer's OS (windows) which is another system or storage device. In this case, your OP acts as a system and a program like Photoshop acts as another system.

I used the word 'system', though probably not accurate or technically correct, I was trying to use a word that would encompass all programing. I assumed that when he said 'Save As' he was talking about saving a file to his operating system. At that point he could close Photoshop (or not). Open it again, and upload the saved jpeg file (-1 or -2) to Photoshop, and then do it all over again and he was unable to detect a change until after doing this 15 times, which seems about right.

 

Yup, that's how I read it too.

My point, which I may not have been clear about, is that there's no degradation when you move or copy jpeg files from one place to another. So, for example, if you drag copies from your hard drive to a flash drive, and then from the flash drive to another hard drive, the files won't suffer any degradation.

 

Right. And my point, which I may not have been clear about, is that there is degradation, and that this guy you linked to was only talking about how a jpg degrades in Photoshop, not how it degrades in general. He never suggests it is only Photoshop where this happens nor does he state that it only happens in image processing programs. I believe you deduced that point incorrectly.

 

I apologize... I didn't mean to start any kind of debate, but seem to have done so.

From reading a variety of sources, it seems pretty clear that a jpeg doesn't degrade when copied from one storage device to another unless the transfer is subjected to some sort of data corruption, which has nothing to do with jpegs per se, but just file transfers of any type.

We may just have to agree to disagree on this point.

 

Well, there is no reason to be sorry about healthy debate.

While I admit that I am not an expert in this, and that the jargon can be confusing. The key is your phrase "unless the transfer is subjected to some sort of data corruption." What you are essentially saying is "the data isn't corrupted when it is transferred unless it is corrupted when it is transferred".

The thing is, there are some lossless transfers with jpgs (within your own computer, for instance) but unless you are an expert who knows exactly what the transfer device does and how, you can not be sure that a data loss has occurred. You say this only happens when there is some sort of "corruption" I don't understand that technical term. All I know is that when the jpg is processed, it will lose data, and data transfer programs can process the jpg in the course of a transfer.

We may just have to agree to disagree on this point.

 

Oh, I'm just not all that comfortable in debating situations. Would have probably gotten an "F" if I'd had a class in debate.

A corrupt file is different than one that loses data through compression. In my experience, it usually can't even be opened or the contents are all messed up if it does open.

I'm not an expert in this stuff, either, but as an ex-tech writer and document and online designer, I have worked with graphic files a lot.