.png vs JPEG for photos

[kallisti]

A friend of mine asked me whether .png or JPEG was "better" for photographic images. Her son is getting into photography and graphic design. Her research indicated that PNG was a better file format because it is both lossless and compressed. It was something I'd never thought about since I output all of my images as JPEG for either sharing on the web or in email. I even output as large JPEGs for printing, unless the service accepts TIFF images.

Is PNG a better file format for sharing pics? Either here or via email? Can Windows users open PNG files in email?

Before I do a deep dive to try to answer the question myself, was curious to hear people's opinions as to the pros and cons of PNG files vs JPEG files specifically related to photographic images.

 

[Nermal]

Historically you'd want to use JPEG, but now you're making me think. PNG was designed for graphics rather than photos, and saving a photo as PNG will result in a large file. However, these days with gigabit connections etc, I wonder whether that's as much of a problem as it used to be...

In other words, I dunno

 

[deep diver]

I think it depends on one's intent. JPEG and RAW are still the standards in photography. I do not know anything about design.

My partially informed/uninformed/misinformed thoughts are:

If we are talking about general purpose file sharing, it seems to me that JPEG is the way to go because virtually any program will open it and the file sizes are smaller. Transfer speeds are only one issue. I'm sure I do not want files as large as PNG taking up space in my phone or tablet.

If he is talking about photography and design, I would go with RAW to the extent possible because it is the photographic standard for lossless files.

 

[Erehy Dobon]

A friend of mine asked me whether .png or JPEG was "better" for photographic images. Her son is getting into photography and graphic design. Her research indicated that PNG was a better file format because it is both lossless and compressed.

Her research is wrong. The common implementations of both JPEG and PNG are lossy formats. I would choose JPEG as the default output format for sharing because it is the legacy digital image format.

Digital cameras from 15-20 years ago generated one file format: JPEG. Same with early cellphone cameras.

Before there was MPEG, there was Motion JPEG, a bunch of JPEG images stitched together to make a movie.

PNG was developed as a royalty-free alternative to the ancient Compuserve GIF file format. That brouhaha finally settled out but the fact of the matter is that JPEG is still the de facto digital image format.

For archival purposes, RAW image files are the best.

Technically all digital cameras actually shoot RAW images, it's in the post processing where many consumer cameras save the captured image to JPEG format -- to maximize storage space. With the widespread acceptance of inexpensive high-capacity digital storage media, the necessity to save lossy still image files has been largely eliminated.

 

[Laird Knox]

I've printed many 24" x 36" images from JPEG files. Some labs prefer JPEG over other file formats. All of my images are shot in RAW format and then saved as either PSD or TIFF. These files are then exported as JPEGs for sharing and printing.

 

[Nermal]

The common implementations of both JPEG and PNG are lossy formats.

While it's possible for PNG to be lossy, it's most commonly used as a lossless format.

the fact of the matter is that JPEG is still the de facto digital image format

Photo format. JPEG shouldn't be used for graphics, only for photos and other 'realistic' content. When you apply JPEG compression to graphics with straight lines etc, they look horrible.

 

[macsound1]

Agreeing with Nermal here. PNG is, by default, lossless. Even when compression is used, PNG does a better job dealing with areas of color, whereas JPEG has a very obvious compression artifacts.

 

[Steven-iphone]

Personally I would use png for images being sent to be printed. Jpeg would be used to share, at 80% with a max long side at 2048px