• Members 562 posts
    Aug. 8, 2023, 6:03 p.m.

    Apart from the usual things (recording family, friends, places, etc.), one thing I like doing is converting some of my photos into colour-only versions (i.e. removing all the grey-scale information to leave only the colours). The results are often very weird, but some of them I quite like as somewhat impressionist images.

    20120502-131442-colour-1 copy.jpg

    20160918-115501-art2 copy 2.jpg

    20170611-075955-colour-sm copy.jpg

    20180806-153212-colour-sm copy.jpg

    For anyone interested in the technicalities, producing a colour-only image can be done in HSV colour by setting V=1. In HSV colour, H is Hue, S is Saturation, V is Value defined as V = max (R, G, B). I use GIMP which it supports HSV colour.

    20120502-131442-colour-1 copy.jpg

    JPG, 3.8 MB, uploaded by TomAxford on Aug. 8, 2023.

    20160918-115501-art2 copy 2.jpg

    JPG, 1.3 MB, uploaded by TomAxford on Aug. 8, 2023.

    20170611-075955-colour-sm copy.jpg

    JPG, 416.5 KB, uploaded by TomAxford on Aug. 8, 2023.

    20180806-153212-colour-sm copy.jpg

    JPG, 915.1 KB, uploaded by TomAxford on Aug. 8, 2023.

  • Members 1662 posts
    Aug. 8, 2023, 8:03 p.m.

    Thank you - that's very interesting and I like the results. These two stand out the most for me, they remind me of illustrations from some artistic childrens books and provide a really different atmosphere from a regular shot. Will certainly have to try this - thanks a lot for the tip!

  • Members 1662 posts
    Aug. 11, 2023, 3:12 p.m.

    I‘ve downloaded GIMP and tried it, like you described it on dpreview (with an additional HSV layer on top) but unfortunately it doesn‘t really seem to work… must have done something wrong along the way. Could you perhaps describe what you do to the top layer after the conversion? That would be great.

  • Members 562 posts
    Aug. 11, 2023, 4:37 p.m.

    Create a new layer above the image layer with the layer filled with white and set to Mode "HSV Value":
    Screenshot 2023-08-11 at 17.29.50.png

    That's it! You should see the result immediately, but you can flatten the image back to one layer if you wish to do further processing.

    Alternatively, you can create a duplicate layer which you set to mode "HSV Value" and then proceed to use Curves tool or other suitable tool to lighten the top layer. That will lighten the visible image without changing hue or saturation.
    To get a "colour only" image, you need to lighten the new layer to pure white everywhere.

    I hope that helps. Please let me know if you would like further info.

    Screenshot 2023-08-11 at 17.29.50.png

    PNG, 372.5 KB, uploaded by TomAxford on Aug. 11, 2023.

  • Members 300 posts
    Aug. 11, 2023, 5:18 p.m.

    I tried, but did not find your technique before you posted this.

    But I got the same result using G'MIC-QT for GIMP addon in filters.
    G'MIC-QT > Color > Channels to layers - Clorspace: HSV, Output mode: New image

    In the resulting image the bottom layer is same as your "colour only" image and the upper layer
    in HSV Value mode is a grayscale value image. You can edit the upper layer or throw it away.

  • Members 1662 posts
    Aug. 11, 2023, 9:49 p.m.

    Thank you very much - now I got it!

  • Members 177 posts
    Aug. 11, 2023, 10:10 p.m.

    I may fire up my DSLR one of these days and copy some slides to post, but the images look much better on a light box than on a computer monitor!

  • Members 510 posts
    Aug. 11, 2023, 10:25 p.m.

    I've done something similar by extracting the channels for HSV hue and saturation and combine them back, simply leaving the value channel out.

    hsv.jpg

    It doesn't work with HSL if you don't use all three channels. But you can get dramatic effects if you extract hue and saturation and use one of them twice, i.e. use it for lightness also. I don't remember if I used hue or saturation here.

    hsl.jpg

    hsl.jpg

    JPG, 5.5 MB, uploaded by meow on Aug. 11, 2023.

    hsv.jpg

    JPG, 4.7 MB, uploaded by meow on Aug. 11, 2023.

  • Members 1662 posts
    Aug. 11, 2023, 10:56 p.m.

    Excellent - looking forward to it! I don't have anything to digitize myself, even though I probably have some of the greatest lenses ever for that... 😅 Do you prefer shooting your slides with a DSLR compared to a high end scanner, like the Nikon Coolscan or Minolta DiMage Elite series?

  • Members 510 posts
    Aug. 12, 2023, 8:39 a.m.

    This made me remember a mistake I made a few years ago. I was going to use curves and a density mask. I clicked the wrong button and instead of loading the mask I applied the curve for the mask to the histogram. Since the mask was for midtones the curve was cut at the ends. The result was surprising. Playing with color spaces and different curves creates all sorts of effects. I posted about it at DPR, so I just link to that.
    www.dpreview.com/forums/post/65440597 (more test images in the replies)

  • Members 1662 posts
    Aug. 12, 2023, 8:50 a.m.

    Really interesting results - thanks for mentioning and explaining it!

  • Members 510 posts
    Aug. 12, 2023, 9:32 a.m.

    Don't know what it can be used for. Maybe a poster in a certain style. But it was fun to discover and play with. And playing is what it's all about, right? 😛

    I actually like this more minimalist result from using HSL. But the right image is needed or it just becomes drab. Think it works for this monstrosity of a building.

    P3080001_darkt_hug-E-curveHSLmod.jpg

    This (HSV) also turned out pleasant.

    p9260218-e-03jpg.jpg

    endpoints.jpg

    Dragging the end points in a bit makes for more subdued tones.

    endpoints.jpg

    JPG, 40.5 KB, uploaded by meow on Aug. 12, 2023.

    p9260218-e-03jpg.jpg

    JPG, 3.6 MB, uploaded by meow on Aug. 12, 2023.

    P3080001_darkt_hug-E-curveHSLmod.jpg

    JPG, 3.4 MB, uploaded by meow on Aug. 12, 2023.

  • Members 209 posts
    Aug. 12, 2023, 12:03 p.m.

    Interesting experiments

  • Members 510 posts
    Aug. 12, 2023, 9:40 p.m.

    This is a bug test and the post can be deleted if an admin sees it.