image Re-size

[williamt57476331]

Hello, I resized a large image to 6M, 300 dpi and sent it for an art jury as a jpeg but found out it was compressed to 425K.  What is wrong? Thank you

[hatstead]

JPEG is a lossy compression format conceived explicitly for making photo files smaller and it exploits the imperfect characteristics of our perception.

[fotografffic1]

JPEG is a lossy compression format conceived explicitly for making photo files smaller and it exploits the imperfect characteristics of our perception.

HUH?!

[Peru Bob]

fotografffic1  wrote

it exploits the imperfect characteristics of our perception.

HUH?!

Read this:

All you need to know about JPEG compression: How does JPEG work? | TechRadar

[fotografffic1]

it exploits the imperfect characteristics of our perception.

HUH?!

Read this:

All you need to know about JPEG compression: How does JPEG work? | TechRadar

You should have included the URL the first time, imho. Then your original post would have been helpful, not cryptic.

[MichelBParis]

fotografffic1  wrote

it exploits the imperfect characteristics of our perception.

HUH?!

Read this:

All you need to know about JPEG compression: How does JPEG work? | TechRadar

You should have included the URL the first time, imho. Then your original post would have been helpful, not cryptic.

Peru Bob just answered your... concise question about hatstead answer...

Allow me to add a third comment:

The jpeg format, with 'lossy' compression does not mean you lose anything useful. It means that it rejects a big part of the information recording which is totally meaningless since we can't see it, even if we can measure it. Our vision is not as sensitive to discriminate colors than tones for instance; saying that our vision has more sensitivity or has relative deficiency in different domains is the same. The smart side of jpeg is that it is perfect for final output (display or print) and for sharing and sending photo files. Knowing the output, you know how much compression you can use without noticing any visual difference. If you have to re-process the file or for archival projects where you don't know which output  can be required, it's better to use lossless compression like in tiff format.