How to reduce file size without losing quality or resolution?

  • I have 2,300+ pictures that I want to transfer to my phone but on their original size they take up a lot of space (6.44gb) I would like to trim is down to without sacrificing quality or resolution. I know it can be done under linux with something like pgncrush. I currently have access to a windows system and all the files are on jpeg format.

    How do I do it?

    Will the copies of the images on the phone only be viewed on the phone's screen, or will you want to print/share them from the phone to some other display?

    Only on the phone's screen.

    The term "TANSTAAFL" comes to mind here. You can run all of these Linux utilities in Windows with a little work. But in general, they're either going to give only a small savings or else require a reduction in resolution or image quality.

    @Bran In which case I suggest reducing the resolution, as suggested by woliveirajr. I can see little reason to have an image resolution greater than that of the phone's screen.

    That's not a duck, that is a swan!

    I didn't have enough "points" or something to answer my own question. I will try it again. @SteveKemp yes probably. :)

    You should always have enough reputation to answer your own question. This answer will probably earn you more reputation.

    You posted the same image twice. There is no difference to be seen, as the image files are completely identical down to the last bit. If you post an actual original and compressed image, we can compare them.

    @Guffa I didn't post the same image twice... why would I do that? You can download the images separately to your computer and check the sizes. http://i.stack.imgur.com/Lz2Ii.jpg http://i.stack.imgur.com/VqHjK.jpg Alternatively you could compile and install the tool I mentioned in my answer and try it yourself.

    I don't know why you posted the same image twice. I did download the images and compared the file contents, and they were completely identical. I downloaded the images that you linked to now, and they are also completely identical.

    Depending on original format, you *might* be able to pick a better lossless compression algorithm. Or more likely not.

    Be aware that uploading to (your favourite image host here) may be affected by them recompressing the image for you, which may make comparisons futile.

    My understanding is that flickr doesn't recompress or convert it but other sites, like imgur, does.

  • bran

    bran Correct answer

    8 years ago

    I have found the answer I was looking. The answer is opt-jpg for Linux. I didn't find it on ubuntu repository. So you have to download the source of littleutils (http://sourceforge.net/projects/littleutils/) which has opt-jpg included.

    To install from source. Download the Tar with wget and:

    tar jxvf littleutils-1.0.27.tar.bz2 && cd littleutils-1.0.24
    

    ...

    ./configure --prefix=/usr && make && make install && make install-extra
    

    You have to be root so sudo su

    I used a duck image for example. The un-optimized file is 1.1M after optimization its 991kb without losing any image quality (to naked eye) or changing the resolution of the image. It might not seem like huge difference (a reduction of 108kb) but with 2300+ images and 6.44gb size on average with the same size reduction can add up to a lot of space. enter image description here

    You can see the original Duck image uploaded to flickr: enter image description here

    And the optimized one: enter image description here

    Can naked eye tell the difference?

    As for how much space I actually saved. You will have to wait some time because I will have to let it run when I am not using the comp. This will take a while and I will remember to report back.

    Just to update on people on how much space I saved. It took about 25 minutes for it to finish and I saved about ~200MB in size.

    So, a 3% savings overall?

    As an aside, you do know that is a swan, and not a duck, right?

    @mattdm Yes not much but now I know that it can be done and not really a "TANSTAAFL" :)

    @RowlandShaw Yes I do realize it but too lazy to change it :)

    Well, I'm not sure I'd call 3% "lunch". Maybe more of a very light snack. :)

    The naked eye can't tell the difference when you reduce the resolution to match the phone, nor if you were to drop the quality from 12 to 8. Those two things together would save you %75, not 3%, of your file size, bringing the whole collection under a gig, with no way to tell without zooming in. (Not sure what quality setting those were originally saved as, but you can usually get an HD size image down to 250kb or so and still look great).

    The first thing to do when comparing quality is to, well, quantify what you mean, and then measure, measure, measure. Nice discussion here of Lr JPEG slider: http://regex.info/blog/lightroom-goodies/jpeg-quality

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Content dated before 7/24/2021 11:53 AM