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iOS app for high-pass filter sharpening

Discussion in 'Image Processing' started by ionian, Jul 22, 2016.

  1. ionian

    ionian Mu-43 Veteran

    397
    May 20, 2016
    Kent, UK
    Simon
    I'm looking for an editing app on iOS that will allow me to apply a high pass filter and overlay it onto the image. Preferable would be layers and masks for this function, but I could survive without it. It is by far my favourite method of sharpening and none of the apps I use can get the same effect.

    If not, do you have any other suggestions for apps with decent fine-adjustable sharpening with masking that will work on an iPad?
     
  2. Andym72

    Andym72 Mu-43 Veteran

    330
    Mar 4, 2013
    Reading, UK
    That's basically the same operation as Unsharpen Mask, isn't it?

    Unsharpen mask is take the image, low pass filter it (blur it), invert it, and merge it back into the original. By inverting the blurred version, when you merge it in, you are removing the info that would pass a low pass filter, and leaving the rest. In other words, you've applied a high pass filter!
     
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  3. ionian

    ionian Mu-43 Veteran

    397
    May 20, 2016
    Kent, UK
    Simon
    Thanks Andy. I didn't realise how unsharp mask actually functioned. Do any ios apps run with this process? I can't see it in the mobile photoshop app.

    To explain, since my PC bricked I've been using the iPad for processing and have actually developed a decent work flow using various apps, but sharpening and noise reduction are two processes I've yet to crack. If I can get these sorted, I may consider giving up my cc subscription.
     
  4. Andym72

    Andym72 Mu-43 Veteran

    330
    Mar 4, 2013
    Reading, UK
    If you want a layers based editor on iOS, then the 3 most popular from what I see are Pixelmator, Leonardo and Stackables.

    I have Stackables, but I don't use it much, I find layer editing on an iPad (Mini) too fiddly. I normally just stick to SnapSeed.
     
  5. ionian

    ionian Mu-43 Veteran

    397
    May 20, 2016
    Kent, UK
    Simon
    Ok thanks, I'll check them out. I tend to use Snapseed as well, along with a bunch of others, but I haven't found one that does everything I want yet...
     
  6. Repp

    Repp Mu-43 Top Veteran

    500
    Jan 27, 2011
    Oak Harbor, WA
    @ionian@ionian It might be worth waiting for a little bit, with Adobe adding Raw editing to LR Mobile and Apple adding Raw editing to IOS 10, we may see some really cool photo editing abilities/apps come out in the next few months.
     
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