If I compress digital photos, will it affect the print quality?

Question

I have a program that will compress the files to a more storage friendly size, but I'm afraid it will take away from details when printed. That has made me hesitant on reducing their size but it is eating up so much room on my hard drive with the mass number of pictures I take. I guess I could save them to a CD, it justs more convenient to have them in the computer. Any suggestions?

Answer 1

Buy another hard drive. Just get an external drive and store them there.

Yes, compressing will compromise the print quality. Since you are asking the question, I have to assume you do not know much about digital images and how they are sized. That's fine - most of us don't.

Although I am no expert, here are the basics:

1) When taking pictures, know what resolution they are. This is usually a number like 1280X1024, 3200X2048, or any other 2 two numbers. This is how big the "canvas" is. Think of the canvas of a painting - some are small, others are large.

2) The quality of the picture you are taking. On most cameras, this is a setting like Good, Better, Best or number of stars (something like that). That is a measurement of how much digital information you are capturing each time you take a picture.

3) The pixel count of the camera you are using. This is usually the "megapixel" number. Pixel are the number of picture elements per square inch (when talking about image pixels). The higher the number, the more pixels - basically smaller, more dense images. A 7.2 megapixel camera has 7,200,000 picture elements per inch, while a 1.2 megapixel camera has only 1,200,000.

So any time you take information away from the original image, you will reduce the quality to a certain degree. It all depends on how low you want to go.

If you are only going to print out 4x6 or 3x5 photos, then reducing the image is fine most of the time. If you printing out 8x10's then you want higher quality images.

Putting images on screen is different too. If you are creating photo slide shows, higher resolution picture are great on high def TV's, but not so great on regular TV's. Lower quality and look better on regular TV than on HDTV as well.

Since you don;t know what the future holds for you, your best bet is to always start with the best image possible and save that original. then when its time to use that picture fro something, you and always downsize a copy of it. However, you can never get the high quality back once you compress it.

For those reasons, you should consider either saving the originals on CD and keeping a compressed copy on your PC, or just get an external drive with more storage capacity.

Answer 2

There are two types of compression, lossy and lossless. Jpeg uses lossy compression, while png and JPEG2000 are lossless (JPEG2000 actually can do both). Obviously lossless compression doesn't affect image quality. But you are most likely talking about jpegs.

For example, some cameras create raw files which are not compressed. Compressing those files for storage is the way to go: saves lots of disk space, without losing quality (can be uncompressed into exactly the same file).

Answer 3

Yes. Compression affects the quality of the image. A little bit of compression (say, 8% in a jpeg) probably wouldn't be noticeable, but the more compressed an image is, the worse it looks.

Answer 4

Yes it will degrade print quality, you should do a test run with a few pictures to see if you can live with the quality. It is better to save them for backup on cd-rw or dvd-rw so you can edit them at your pleasure. Alos a good idea is to get an external hard dirve. I know most people like to have them on their computer, but not much sense unless you use them all often or for presentation. Good luck.