The JPEGmini application can take a jpeg file and compress it to around a third of its original size without any quality loss. The pro version can work with file up to 128 megapixels. Some of my larger panoramic images have been around 80 meg in size when thrown into JPEGmini, the result is a staggering 42 meg reduction in file size!
So how far can it go? As an experiment, I tried to see the benefits of continuing to run a jpeg through JPEGmini until the result reports no further compression available. The window will show how much has been removed. Once that reads 0.00 then I have my final image. So I took a portrait image from a recent shoot to test out.
The original Raw file is circa 24 meg in size.
I exported the Raw to a Jpeg at a full 100% quality setting. This produced a Jpeg with a file size of 17.429 KB. Just short of 17.5 meg.
I then ran it through Jpg Cleaner to remove the metadata. Not surprisingly this removed very little, the size was now 17.417 KB.
I then ran the Jpeg through the first pass of JPEGmini, this reduced the file down to 3.470 KB.
I then ran the file through Jpg Cleaner each time, as I have found this removes the flag that tells JPEGmini that his already been JPEGmini’d. You can then continue to JPEGmini the file until the result reports 0.00 removed.
So finally the resulting file was crushed to 1.838 KB, just short of a 2 meg file. If this was done to a file exported at 2000 pixels on the long side the file size would be around 500k, less than half a Meg.
There was some quality degradation if you do this. Mostly in very fine detail, however, you can see this only when you zoom in to 100%.
So how does this equate to a full shoot package? Is it worth the extra time to keep passing the files though JPEGmini?
So I timed the process. I exported a shoot of 244 images all at 2000px on the long side. The folder size was 717 Meg. The export took around 5 minutes.
Throwing the folder into Jpg Cleaner took 4 seconds and removed 2.7meg. We were down to 714 Meg. The Jpg Cleaner app was left open to quickly run the sequence again once the first stage of JPEGmini was done.
The first stage of JPEGmini took just 47 seconds to complete. Jpg Cleaner took 2 seconds to clear the JPEGmini flag from the files. The folder size was down to 135meg in size.
The next few passes through JPEGmini will get faster. There will be an increase in files that JPEGmini cannot compress any further. These will be skipped.
JPEGmini = 34 seconds | JpegClean = 2 seconds
JPEGmini = 33 seconds | JpegClean = 2 seconds
JPEGmini = 17 seconds | JpegClean = 2 seconds
In total, the process took under 3 minutes to compress to a point of diminishing returns.
The folder size was now down to 76 Meg in size. Just over 10% of its original size and about 65% of the JpegMini’d folder size.
There is some degradation but again you can see this when you zoom in to 100%. As these are for use on web pages and social media this is not too much of an issue. If the work was for printing then I would not attempt this secondary process.