JPEG to tiff

tetanicwhisper · Apr 1, 2011

Hello, i am new to these forums and recently picked up my interest in photography. I learned that Jpeg is a lossy format and had a few question about this format. Now on i am taking pictures in Jpeg and in RAW, but for my previous pictures i was wondering if i convert to tiff for editing will i stop the quality loss? Will picture quality degrade if it sits on a hard drive? or is that a result of my hard drive wearing down?(4+ years) Another thing i would like to ask is if i move a picture from one folder to another will it lose quality too?

Mike

reedshots · Apr 1, 2011

If you shoot RAW you will get the most out of your editing software, if you shoot JPEG not so much but still not bad.
As for image quality on the hard drive, no - moving it, leaving it there for ever will not hurt the quality (unless your hard drive is corruted and it damages the image file)

KmH · Apr 2, 2011

A JPEG image file will not degrade while stored on a hard drive becuase it is a JPEG, but because of degradation, if any, of the hard drive media itself.

JPEG only degrades to some degree each time it is saved. How much it degrades depends on the 'Quality' setting used for the save.

Realistically, it takes about 20 saves before a human can see any degradation cause by JPEG's lossy file format.

Consider the issue that JPEG only allows for a 8-bit tonal depth in each of the 3 color channels: red, green, and blue ( or 24 bits total, 3x8=24), so any JPEG converted to TIFF will also have an 8-bit depth, whereas an image originally made as a Raw or TIFF file can have a 16-bit depth.

Digital cameras that can make images having a Raw file type make iomages at either a 12-bit depth, a 14-bit depth, or can make images at both 12-bits or 14-bits. It is when the images are converted from Raw to another file format that they can become 16-bit depth files. The added 2 bits or 4 bits do not contain any additional image data, and instead are used for metadata.

The_Traveler · Apr 2, 2011

KmH said:
JPEG only degrades to some degree each time it is saved. How much it degrades depends on the 'Quality' setting used for the save.

Realistically, it takes about 20 saves before a human can see any degradation cause by JPEG's lossy file format.

This means every time it is actually 'saved' not viewed and 'closed.'

Garbz · Apr 2, 2011

Bits are bits. Bits don't change. You can move them, copy them, store them, and they will remain the same for years.

JPEG is a lossy compression algorithm. This means that every time an image is compressed it will lose a bit of quality. This does not mean decompressed. You can open the picture which decompresses it to display, and when you close it the computer just dumps the decompressed data with no change to the original JPEG file. However if you open the JPEG and then save it, at that point you will be recompressing and suffer another small layer of loss.

Your worry is if you go back and re-edit the same file over and over again. I have been happily storing JPEGs for years, but I use RAW and TIFF while I'm editing the pictures in photoshop. When they are finished, I save to JPEG for long term storage to save space.

djacobox372 · Apr 3, 2011

Every time you change/save a jpeg it degrades further, so if you're going to be editing it save as .tiff. When your edits are done you can save the final image to jpeg to save space.

Joseph Westrupp · Apr 8, 2011

tetanicwhisper said:
i was wondering if i convert to tiff for editing will i stop the quality loss?

As long as you keep saving in TIFF format, the file will retain all the information the original JPEG had (TIFF is lossless).

tetanicwhisper said:
Will picture quality degrade if it sits on a hard drive? or is that a result of my hard drive wearing down?(4+ years)

As others have said, if you're just storing it, if any information is lost, it is due to the hard drive itself. To protect against this, store multiple copies (one copy on a local hard drive and another on either another separate hard drive of your own, or online).