Copying and pasting pics

[ICIT2LOL]

Just a quick query - re copying say a single pic/s or a whole folder to a new folder - does the copying and then pasted pic/s have any degradation in quality of the pictures so treated.

I ask because my partner is moving pics one by one from one site to an existing folder and tells me someone has told her that doing it as a mass movement degrades the copied and then pasted picture/s.

I have tried it on my machines and to be honest I just cannot see if there is such degradation to me copying and pasting is very little different than moving one picture at a time for a collection to a named folder.

Anyone who is clued up on this I would appreciate your advice - not that I am going to argue with her.

I ask because to me the pictures are digitally produced and apart from the system having glitches while doing this the reproduction would have to be exact or at least so close to exact so as not to be discernible to the naked eye.

 

[Barman58]

There should be no degradation if you are using a file manager to do the move, or copy.

If you open a JPEG file, (which uses a lossy compression algorithm), in an editor and save it somewhere else as a copy there is a good chance that the JPEG will be re-encoded and thus will degrade.

Other file formats vary in the amount , if any, degradation you get when editing, with a lot of formats having no compression or non lossy compression they are unaffected by being re-edited

Edit

One thing to watch is you may get a loss of quality if you rotate a JPEG image, unless you use specialist software

 

[ThrashZone]

Hi,
I've never seen any issues with quality loss
You can cut and paste but I rarely do that,
I would usually use right click drag and drop and use move too from the list of options

I would usually only copy and paste if going from 1 computer to another or really copy too with right click drag and drop.

 

[ICIT2LOL]

Thanks Nigel and Mike I get the general drift of that - being one of the format the pic is in ie JPEG.

Now if I can get to her machine and check out what formats the pics are in it should tell me what that other fellow was telling her. Now most of my pics are in PNG format when I click on the Properties of the pic and in my experience I have never seen any degradation in my stuff and a lot of my pics have followed form machine to machine usually via a USB stick or on odd times an email.

Addit I just checked a few of her pics and they are all JPEG - suppose it is the brand of camera.

But thanks again for the heads up.

 

[ThrashZone]

Hi,
I have quite a few jpg's matter of fact all my wallpapers are jpg
The only time you may run into issues is resizing them either direction.
Otherwise nothing wrong with jpg's as long as you save them from an original project file to the exact size needed for the display it's for.
And it helps by using a real photo editing program and not Paint....

 

[Barman58]

JPEG images use a lossy compression algorithm which means that data is lost every time you save them, this is a fact that cannot really be changed. If you have a camera that only produces JPEG images then creating a not lossy master copy could be a useful trick if you intend to make a number of versions of the file. The easiest method is to open the JPEG in your favourite editor

Set the settings for the save as .PNG to the best quality and save the file as PNG.
Close the JPEG file without saving and archive it
Use the .PNG file as a master and save the edits as .PNG and you should not see any degradation.


An interesting experiment is to load a JPG file into paint and then save the file adding a suffix, 01 ....02...), repeat this a few times (always open the last saved file each time) and you can then see the amount of degradation you Get.
After a few open/save cycles it's quite possible that the file will be totally ruined.

My cameras are set to take RAW images which take up to 32bits per pixel, which can mean image sizes of over 35MB per image but they can be edited indefinitely without any loss of quality - of course the downside of this is that file sizes increase with some types of editing, I have seen panorama images approaching ½Gig in size

 

[ThrashZone]

Kind of depends what you'd be using them for obviously
I doubt I'd be using or wanting to use a bunch of 32mg files for a desktop slide show or even 1 for a wallpaper
I believe I try to stay below 1mg.

 

[ICIT2LOL]

Thanks again for the info now I could save the JPEG's to PNG but the sheer number she has would take a lifetime to do as she is shutter crazy when it comes to pics.

My own like I said are PNG and I use a lot for wallpapers too and don't notice anything out of whack except that if I pick the res for any particular machine the wallpaper pic is always a tad smaller than what I save from wallpaper sites.

 

[mitchell65]

Just to add my two pennyworth, you can batch convert JPG files to PNG with Irfanview free edition. Works well, I have used it a lot.

 

[ThrashZone]

Once an image is jpg/ jpeg turning it into a png is a waste of time the image is already limited.

There is also a huge difference in taking a picture with a camera and snatching one off the web

There is absolutely nothing wrong with jpg images as long as they are not resized and are the resolution you need for the display.

 

[mitchell65]

Once an image is jpg/ jpeg turning it into a png is a waste of time the image is already limited.

I agree but I thought, obviously wrongly, that Mike wanted the images in a format that he could edit and save without loosing quality. My thought was that whereas a jpeg is compressed and therefore looses quality everytime it is saved a png image doesn't so that would be his answer!

 

[ThrashZone]

I'm Mike
John asked the question
Either way there is no gain in changing the file type the files are already hosed.

 

[Barman58]

If you are going to edit a file then you should never use Jpeg,

it's a simple fact of life, even at the top quality setting you will loose data every time you save the file and in a lot of circumstances just rotating the image will also cause data loss

The only use for JPEG images is for the last stage in producing files for web use and that is no longer really needed as the replacement for JPEG to solve these issues is already available, PNG was developed for this very reason, plus it supports alpha channels which allows better Matting