[Imaging] An objective review of the JPEGmini webtool
Their sample images You can download their sample images. On their website you cannot see the difference between their 10Mb file and their 1Mb file. Hardly surprising since it’s a 3000×2000 file they display in a 600px wide frame. That way you can’t see the detail that you are losing. On very close inspection in photoshop on 100%, i couldn’t see the difference either, but the difference was just some noise. The catch is that their sample files are crappy quality files that are ideal to be compressed, leading to an insane extra compression of 10Mb to 1Mb. A nice feat, but the compression is lossy (due to the nature of a JPEG). So what do we lose?
TestsI have tested a Golden Thread Device Level Target. This target is used for measuring the performance of your camera on a variety of image quality aspects. This target has a few features we will test on. Let’s test the standard deviation (noise), color encoding, oversharpening and sampling efficiency (or sharpness).
Test MethodTo test the images, we use the free on-line image quality assessment tool called Deltae (http://delt.ae/). You can just drop your images on the website and it will assess them for you, and the images have to contain a test target.
Retrieving the JPEGmini from their websiteI just uploaded the image and got the following file. On first sight, i couldnt see real difference, also, it nicely kept the EXIF info intact.
Uploading the file to the Deltae website.Uploading is easy, just drop the two files on (the original and the JPEGmini version).
Results!The Deltae quality analys tool gave me the following results that I’ve put in a table:
|File||File size (Mb)||Noise (stdev)||Color encoding (deltaE2000)||Sampling Efficiency (%)||Oversharpening (%)|