Image Quality

Got to discussing image quality in an online group today and how one person’s pictures looked fine on export but as soon as the agent uploaded them to MLS they looked like crap.

For some reason JPEG quality is a scale of 0 through 12, 0 being the smallest file size and lowest quality and 12 being the largest file size and greatest quality.  I generally do everything at 10 as it gives a great quality and a significantly smaller file size than 12.

So I decided to do a little experiment.  I generally provide much larger files (at least 1200×900) to my clients, but these will work for here.  Click any image to see a larger version.

Here’s an exterior shot with a quality of 10 (it’s an 800×600 file and 416KB in size):

Here’s that same shot compressed down to Quality 0 (again, 800×600 but now only 103KB):

You’ll note there’s some banding and the sky is getting pixelated.

On interiors it gets even more noticeable.

This is an 800×600 interior, quality 10, with a file size of 186KB:

Here’s the same file, compressed to Quality 0, now with a file size of 50KB:

Notice how splotchy the ceiling got, and the backsplash?  Eiwww.

I understand why an MLS service might do it — file size.  If every listing uses all 25 (for example) pictures, and the pictures are 500KB a piece, that means each listing requires a storage space of 12.5 MB.  However, if you can compress those images down to 100KB, then each listing only needs 2.5MB of space.  Disk space is cheap, but it’s not free.

And here’s a single image of the two images side by side.  Click for a larger view.