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The Colours of Black & White Part II - The Conversion

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Victor W. is a group administrator Victor W. says:

I probably more than annoyed a few of you by 'blithering' on about shades of grey in the first post. Well fear not, now I'm going to discuss the conversion process....
"Thank God for that" - yeah I heard that, here we go:-


(If you missed it, here's Part I)

Right, we now we've got lots more shades of grey, but how do we get that into the images. I pretty much came about this just by clicking and experimenting in an old copy of Paintshop v.8.

The following image shows the original along with several commonly used black and white conversion techniques. I've included the histogram for the Red, Green and Blue channels as well as the Grey and Lightness values and the number of colours your left with.

B&W Conversion Methods

The original image contained 154,774 colours, (much less than the possible 16,777,216 colours we have a maximum of.) Your original could obviously contain more or less colours depending on the subject. From the histogram you can see a nice spread of Red, Green and Blues as well as the Greyscale and Lightness values.

When we convert to B&W using greyscale, we get exactly that, and only 256 colours. If you use the desaturate we now only have 253 colours! I don't know why that happens but look at that big spike on the graph, something went wrong. The next conversion is the 'channel mixer' option. I used a standard 30,60,10 conversion, (to simulate the human eye spectral sensitivity), so it is pretty much the same as the 'grayscale' conversion. The only handy thing is that you can alter the amount of Red, Green and Blues from the original therefore simulating the effect of using coloured filters for black and white film images. Still only 256 colours though.

Then we get to the conversion I came up with whilst playing around with Paintshop - All 2,175 of them! That's 8 and a half times as many greys!!

The final image I came up with here has 3,427 colours.

Glass, Metal, Wood

Depending on your original image, the colour shift amounts, curves etc. you can get thousands of shades! Very handy.

Right onto the conversion.

If you've used paintshop, photoshop etc and have an understanding of layers then this is a breeze - If you don't, well I'm afraid I'm not going to teach you, it'll take too long for one post. Read the help or check some tutorials online or simply ask.

Make sure you've got your image loaded up and either perform a copy and paste or duplicate, (so that you don't alter your original - always a good idea.)

Now add a channel mixer layer to that image.
Layer(s) -> New adjustment layer -> Channel Mixer

Use a standard Red=30, Green=60, Blue=10 for now and make sure you check the monochrome box.

Now add a Colour Balance layer, I usually start with the values 5,0,-5 for the shadows and 3,0,-3 for the highlights. You can adjust these later but remember to make subtle changes to these - you'll only regret it later when you come to use curves!
You can however make larger changes to the midtones later to give a colour change such as sepia, (20,5,-20 is a good start for subtle sepia.)

Right, got that bit? That was easy wasn't it. But we've still only got 256 maximum colours for now.

Now either copy or duplicate the original and make sure it sits above these layers you've already created.

Now change this new copy layers property to 'Luminance' for paintshop, 'Luminosity' for photoshop.

You should now have from top to bottom

Copy Image - Luminosity or Luminance (photoshop/paintshop)
Colour Balance - Adjustment Layer
Channel Mixer - Adjustment Layer
Original Image

Doesn't look any different does it? (Some of you may notice the luminance change.)

However if you now flatten this image, (either flatten it or copy merged) and make sure you either save it or paste as a new image, this image now has a darn sight more than 256 colours and yet still look black and white. (OK, on photoshop it may look slightly blue - you can change this colour shift on the original layer work, try -3,0,3 for the shadows.

In paintshop there is a facility to 'count colours used', I'm not sure if that feature is on Photoshop, someone will have to confirm this for me. Also the histogram function is rather nice in paintshop I assume there's something similar in photoshop.

Well how has that helped me?

On the original layers work, you can now adjust the image filtration through the channel mixer, (red filter, yellow filter etc. or as I do, adjust to suit.)

You can adjust the colours layers to alter the 'coolness', 'warmth' or 'neutrality' of the image.

The Luminance, or Luminosity layer is the masterpiece here - it's what gives us all our colours or shades of grey.
Instead of copying the original image in there, try a HDR or tonemapped image and adjust the opacity. Or maybe adjust it's curves layer, or brightness, or blur it a little - You'll start to see what you can do with the image now, a hell of a lot more than you could with 256 shades that's for sure!

Even if you flatten the image and start doing some more post processing afterwards, as you've got an extended range of greys, you can do a lot more. If you start seeing funny bands of colours or colour fringing you probably overdid it at the shadow/highlight layer part, (I did warn you!), so adjust the original layer work.

If this is not looking so straight forward to you, have an experiment with the images you've produced, you'll soon see the advantages over the other conversion methods.

Here's some other images that I've used this with:-

9,669 colours

Getting Older


1, 543 colours, layered with a HDR copy on the Luminosity

Lighter & Tobacco Case B&W


4,088 coours, layered with a HDR copy on the Luminosity

Church Door Final B&W Conversion


Now you can see how I seem to get so much from my black and white work.

If any of this doesn't appear so straight forward, do ask. Have an experiment with it all too - it's how I came up with the idea and some of my images.

Welcome to the world of extended digital Black & White.

(If you didn't get any of this, either try again or stick with the 'greyscale' click - Told you it wasn't a straight 'forward click', but isn't all the better work reached on effort?)
Originally posted at 2:48PM, 14 January 2009 PDT (permalink)
Victor W. edited this topic ages ago.

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The Laddie is a group administrator The Laddie says:

In Photoshop you can automate most if not all of these steps to an action. So you can reduce it to a click or even a press of one button....

I'll go though this and see if I can optimize an action and make a droplet out of it for people to download
ages ago (permalink)

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Victor W. is a group administrator Victor W. says:

That's a pretty good idea Laddie. You don't want to automate too far though, as you want to keep the variability to it. That's part of why it works so well, infinitely variable process.
ages ago (permalink)

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The Laddie is a group administrator The Laddie says:

Yeah I have already done it now...

Thing I have done is to keep it in seperate layers so the user afterwards can adjust them without having to do it all over again cause the action merged the layers

On CS4 I used a high contrast image of my baby and made 2 copies. One used your action and the other I used the gray scale... Man what a differance. (posting sortly)
ages ago (permalink)

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Victor W. is a group administrator Victor W. says:

Brilliant!
I'd really like to see what everyone comes up with using this method. It's opened up my world of digital B&W.
ages ago (permalink)

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The Laddie is a group administrator The Laddie says:

Victors conversion

I noticed that the image had some grain and when its in gray scale it gets worse but in your conversion its fine (at least to the original image)
ages ago (permalink)

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Victor W. is a group administrator Victor W. says:

There should be a smoother transition due to the extra greys you obtain.
The fun really starts when you start playing around with contrast levels using curves etc. Makes a huge difference.
ages ago (permalink)

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Em0312 says:

Excellent tutorial. Well explained and easy to follow. I'm happy to report I understand this and will be able to use this method. Thank you Victor, much appreciated.
ages ago (permalink)

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Victor W. is a group administrator Victor W. says:

Hurrah! I'm so very pleased!

I tried desperately to make this easy enough to understand and hence the colour analysis of the first part. It doesn't make much sense without it, and when you first do it there doesn't appear at first hand to be much difference. (That was the point I was trying to make, we can't see the difference in the close greys, but the computer and software can.)

The difference lies in what you can then do to the image afterwards as far as contrast etc.

I'm so chuffed! Thankyou!
ages ago (permalink)

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LongShot1972 says:

Ok, for those with photoshop, here is a simple plug in to count colors.
www.simpelfilter.de/en/analysis/colorcount.html

When you run it.. it will read Number Of Colors but it will be in German. Just read the numbers and thats it.

Heres my little processed picture. 6071 Unique Colors. It was around 14,000 before saving for web at 60%

Shy
Originally posted ages ago. (permalink)
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Victor W. is a group administrator Victor W. says:

That's excellent stuff Brian.

Have you found it gives you better control over the final images?

Oh, and thanks for the link on the photoshop colour, sorry color ;) counter, that should really help a lot of users out.

(Maybe that's why I haven't seen more than 256 colours in peoples work? I assumed as my old copy of paintshop has a counter and decent histogram functions that newer editing software would have it.)
ages ago (permalink)

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Mauritius100 says:

I agree and second what Em has said - excellent tutorial - explained extremely well!! And although I am not in a position to try it out now ( no paintshop and pc too slow with gimp) I can assure you that I will be looking this up again when I have the means to try it!

Thank you so much Victor!!!

PS Even your photos introducing this are works of beauty!!
ages ago (permalink)

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Em0312 says:

Cool, thanks Brian, the plug-in works perfectly!
ages ago (permalink)

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LongShot1972 says:

You all are very welcome. As far as control, I am still really new at PP on Pictures. All my experience in PS is still based in Graphics type work. I cant really say about control but I do see more definition. Usually when I shoot something I think would look good in B&W, I would switch between Chrome and B&W on my camera and take 2 of the same shot. Got to experiment more and count a original B&W cam shot to see what it says.

The pic I posted had a bunch of bright colors that seemed to transition well this way. Check my Photostream to see the original.
Originally posted ages ago. (permalink)
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Victor W. is a group administrator Victor W. says:

Thankyou Mauritius!
I'm sorry I couldn't figure it out for a feely available package. (Spent hours on GIMP and couldn't get anywhere near!), but I am glad that it'll come in handy.

(I remember all the issues with my darkroom, got a 35mm setup, then went 120 - new enlarger, new cameras etc. Then wanted bigger prints - new trays etc. etc. Then tried large format - new enlarger, new film processors - the list goes on and on. Now I'm doing exactly the same with digital, the computer upgrade cost more than the camera!)

Hi Brian,
I'm happy you found it useful. You will come to see how much it helps as you progress with digital B&W. (The in-camera B&W is the same as greyscale, again only 256 colours.)


I'm glad that everyone has found, (will find), this technique handy.
I love digital for its spontaneity, but was really dissapointed with the black and white imagery, now I'm more than happy with it!
ages ago (permalink)

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LongShot1972 says:

Victor, to let you know, I have tried doing psudo HDR to the luminessence layer and then after I collapse the pic. I personally feel applying HDR looks much better after you collapse it. The last 2 I added to the group.. I did your conversion with your sepia, then used a kelvin plug-in to warm it up more. Lastly Photomatix. HDR didnt seem to pop as much until you hit it on the whole picture.
ages ago (permalink)

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Victor W. is a group administrator Victor W. says:

Hi Brian,

It all depends on the content of your original HDR as to what effects you will get. If you use certain 'realistic' HDR methods, you may find that there is virtually no difference to the image using this method. (The luminance of the 'realistic' HDR being compressed to show both shadow and highlight flattens the light range.)

I use 'qtpfsgui' which is a free package and mainly use two of the operators for tonemapping - 'Mantiuk' for the flattened luminance and 'Fattal' for the increased contrast and colour. These are then 'overlayed' in a 100%/70% mix to give me the 'base' image. This gives me the extra clarity of detail I require for the luminance channel to enhance the original image sufficiently.

A lot more work's required for this method, but I find it's worth it.

There's an infinite amount of possibilities that can present itself with this technique so it's just a case of finding what 'works' for you.

Thanks for the feedback though.
ages ago (permalink)

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Mauritius100 says:

Back again - to refresh my memory and try it out.

Using Gimp - and stuck right at the very start - and then read your comment that you haven't been able to get it work with Gimp.

Well Victor - if you haven't been able to do it that way then I'm convinced that I won't be able to ............ oh well - will have to try something else!! But will be back to this someday!!
ages ago (permalink)

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Mauritius100 says:

Have had another go with Gimp. Not quite what you did, Victor ( but managed to do Channel Balance and Channel Mixer and then substituted something different for luminance). The result is this ( but not sure that at the end I get a better result). Any reaction would be welcome. Memo to self - must not try and do this while something is cooking on the stove ; - ))

DSC_9864gimp
Originally posted ages ago. (permalink)
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Victor W. is a group administrator Victor W. says:

Hi Mauritius!

Yeah, no good playing around post-processing with something cooking other than your pictures! ;)

You actually chose something to convert that's harder than most of the stuff I've done - landscapes. Notoriously difficult to get a good B&W landscape because of the similarity in colour lightness and tonal value. Luckily with digital there's the option to play around with the channel mixer which is like using B&W filters with film, (yellow, orange, red, light green etc.)

You did well with this though, the sky detail has been held well and the tonal range from background to fore is very well processed. (Plus you've always had an eye for 'line-out' making your pictures more three dimensionally representative than most! Would love to see more landscape work, still have your salt-pans picture in my head.)

Anyway, between being busy playing with my 'new' flash, (and building another! I know, but I need at least another - one light and a reflector isn't quite cutting the mustard), I've had another play with GIMP. Especially after seeing this thread pop up again last week.
(Felt awful I didn't try harder the first time!)

*************************************************************************
I've managed to get a similar process to what I use with paintshop!!
*************************************************************************

You have to go about it in a different way by using overlays but it gives the extra 'colour' greys needed for further processing. Hopefully I'll have it nailed down for another tutorial posting in the next day or two. (Just need to make it easier to follow.) The first tests show the same extension in tonal range as the original version. It also seems to give better options for pseudo split-toning, (something I used to love doing with wet B&W darkroom prints.)

So bear with me and I'll have that posted up as soon as.
ages ago (permalink)

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Mauritius100 says:

Hi Victor

No need to feel awful - in fact that would be dumb!! Why should you feel that you have to provide all the information and know everything that we wish to find out.; - )) It didn't do me any harm looking around on the net and playing with gimp - quite the opposite in fact ( except for burnt dinner).

Glad to know you are busy with making things for you!! That means there will be new photos to see soon!! Looking forward to it!

If you do have time to do a black and white gimp tutorial that would be typical Victor generosity! But you take as long as you want to prepare it - and don't neglect your own priorities and direction!! Meanwhile I'll keep playing with gimp and see what I can discover.

All the best
PS Thanks for the compliment ; - ))
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Victor W. is a group administrator Victor W. says:

Thanks Mauritius.

You know me though, ever willing to help. (Especially this GIMP software, it's great for free but takes some workarounds to get it quite right!)

Anyway, you're on the right track with the 'channel mixer' route.
Still having issues working out all the adjustments as you don't have adjustment layers in GIMP.

Quick start if you want to have a go, (as far as I've got straight!)

* Load your image

* Duplicate layer, (so you have two copies.)

* Goto Colours -> Components -> Channel Mixer

Use this as you would for a normal B&W conversion, red=30%, green=60%, blue=10% for 'normal' human vision. (Adjust red higher for a red filter effect making sure this and the other channels add up to 100% - so adjust accordingly. Green higher for a green filter etc. Careful of increasing blue, it's the noisiest channel.)

* Goto Colours -> Colour Balance
Select shadows and adjust the sliders so that red = -10, green = 0, blue = 10.
Select highlights and adjust for red = 10, green = 0, blue = -10.

This gives the blue shadow, sepia highlight offset for apparent neutrality.

Now change this B&W conversion layers attribute to Saturation

You should now have a B&W conversion that has the thousands of possible 'greys' available with better tonal rendition.

For the HDR luminosity layer, (should you wish). Load the HDR, copy it, go back to the original B&W conversion, paste as a new layer and set it's attribute to Lightness. That'll give the extended grey B&W + HDR look. You can now adjust the opacity slider to reduce the HDR look to something suitable. (Careful of flattening contrast - something that HDR is terrible for!)

That's as far as I've got for now. Unfortunately you have to be careful as you adjust each step as GIMP doesn't allow adjustment layers so for example, you can't go back and adjust the B&W filter offset. It gives the extended colours of grey effect as the original tutorial though.

Flatten the final image when you're happy and then you can adjust brightness/contrast/curves on this image afterwards. (There are truncations in the palette doing this afterwards unfortunately - I'll try and work out a way around this.)

That's as far as I've got, (keeping it fairly simple!). It's all about layers.
I'll post when I've got it fully cracked. Nothing else is being effected doing this - one thing I have plenty of is 'time' ;)
ages ago (permalink)

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Mauritius100 says:

Victor - that was quick. And I came here to post a second try.

The first bit I did as you did - using channel mixer - but I forgot to do the next bit ; - )) Will post it temporarily - whilst I prepare salad and then try the other steps (salad faster and can't get burnt!!)

DSC_9881bw.

And thank you so much!!!
Originally posted ages ago. (permalink)
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Mauritius100 says:

Hi Victor - and anyone else reading this.

Have been playing around some more and trying to follow your instructions.But not sure I am doing it right. Would you mind running through this and confirming that I am doing it right ..

I have been loading image - duplicating it to get two layers.

Then on the duplicate doing the Goto Colours -> Components -> Channel Mixer as you have described to get a result that I like.

And then on the same layer as the one just worked on doing the Colour balance and selecting the shadows with the settings above ( or a slight variation but with the numbers being -x, 0, +x) and then afterwards selecting the highlights and applying the opposite numbers ( +x, 0, -x )

Sometimes I use curves at this point.

When the layer attributes are normal I am happy with it.

Should I use the same layer to change the attributes to Saturation?
Should doing this produce a much lighter image ( sometimes it does)



For the next part I am lost. "For the HDR luminosity layer, (should you wish). Load the HDR, copy it,..........."

What is the HDR luminosity layer - is it the same photo - or another shot of the same scene shot from the same position with slightly different exposure. And if it is in colour - what black and white conversion method should be applied?

Once again - a big thank you Victor - the results are much better already ..............
ages ago (permalink)

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Mauritius100 says:

The latest try

DSC_9175bw3.
ages ago (permalink)

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Mauritius100 says:

Rereading the original tutorial for paintshop decided that I should be doing each step on a separate layer so tried to do the same photo with one layer for each bit ( one for channel mixer - normal attribute, one for colour balance - saturation attribute, ? one for luminance - couldn't find gimp equivalent - merged them down one layer at a time)

I think the final result looks the same.
ages ago (permalink)

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Victor W. is a group administrator Victor W. says:

Hi Mauritius.

Ah, yes. I've noticed that sometimes the image is lighter too. Still trying to figure out a suitable workaround. (You can adjust the brightness/contrast afterwards.)

The HDR layer is if you want to add the detail enhancing feature that a HDR of the image can bring. You can also place a copy of the original colour image in this layer - keep it in colour as you're using the colour values lightness values on this layer. (Hence the lightness attribute setting.) This should balance the error of the saturation layer in this instance.

When and if you alter the curves of the image you're best to copy visible, paste that as a new image and apply your curves to that. If you apply it to the B&W layer you risk the chance of reducing the contrast range with only the limited 256 grey palette. This can be seen by highlights 'clipping', (in the whites), and lowlights 'blocking', (in the shadows).
(This can be seen in the clouds highlights and in the shadows of the trees in your image immeadiately above.)

Keep at it as you're almost there. The palette is extended on the above image to almost a thousand colours!
ages ago (permalink)

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Mauritius100 says:

Thanks for the encouragement and extra help Victor. I really do appreciate it!! Ta too for the count of the number of colours - can gimp do that as well?

The one above was working on a single layer - should doing each step on a different layer and then merging them work better? ( It didn't seem to make any difference)

Am off to try again!! ( I get marks for persistence ... ; - )))
ages ago (permalink)

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Victor W. is a group administrator Victor W. says:

Yep, you're on the right track!
You won't be able to see the difference on the multiple layers but the extra greys are in place for further adjustment. Remember the software alterations will be far smoother than a 256 colour B&W allows. (See the original 'Part I' image - you can't see the difference between the 'greys' but the computer does.)

I simply cannot get GIMP to allow me to place constant variablity to this routine. I've had a look at the scripting software to make a plug-in but that would take some work from scratch.

So I've had another thought. Use the example given for GIMP as is and treat that image produced as your 'negative'. (Much like a film camera as you've already made your filter adjustment using channel mixer.)

Use this image to tweak further, such as adjusting curves, contrast, brightness etc. much like a traditional B&W 'print'. As you already have the extended range of colours in the B&W conversion, (which depends on the colour information you had on the original camera capture.) You can also alter things such as sepia/split toning etc. afterwards because of the extended palette. (Asking the software to sepia shift thousands of 'greys' is far more successful than only 256.)

That way clipping, blocking and banding will be far more avoidable.

I do hope that helps because you've pushed it along nicely and the images are obviously holding far more information than a standard 256 B&W allows.

I'll check on the GIMP palette count, but I don't think it does it. I'll get back to you on that one.
Originally posted ages ago. (permalink)
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Victor W. is a group administrator Victor W. says:

Aha - Goto the menu/toolbar

Select Colour -> Info -> Colourcube Analysis

That should tell you how many colours you've ended up with.
ages ago (permalink)

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Victor W. is a group administrator Victor W. says:

^^^^^^^^^^^^^^^^^^^^^^^ Don't miss the Colour Count Above ^^^^^^^^^^^^^^^^^^^^^^^

Another thought - Save a simple desaturated version of your image, (call it something like "Title_B&W_desat_temp"), and use this to compare with your colours of B&W conversion. You should instantly see a difference and especially with the further work with curves etc.

Anyway, I must dash - had a list of chores I should have done and I need to get dinner on soon for Teresa.
Yep, I'm just the 'kept man' aren't I!? At least one of us is employed ;)
ages ago (permalink)

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Mauritius100 says:

Thanks for the latest info - will try these out shortly - but still having a few problems with the previous instructions.

for hdr layer - when I try to copy paste the original as a new layer - it goes as a floating layer. I then anchor it to the new layer - but can't see how to put it's attribute to lightness . Would it be value and not lightness as the attribute by any chance ?
ages ago (permalink)

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Mauritius100 says:

Thanks so much Victor - hope dinner will not be late!! If it is do blame it on me!
ages ago (permalink)

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Victor W. is a group administrator Victor W. says:

Yep, sorry. (Foibles of GIMP!)

Paste it as a new image and then copy it back and paste as a layer. For some reason GIMP anchors it?!

Really must dash!
ages ago (permalink)

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Mauritius100 says:

Thanks once again Victor - your method certainly works - and you have now got it to work on Gimp too. We don't call you Vicapedia for nothing!! According to Gimp there are 3867 shades of grey in the original b & w. You're a genius - and a great teacher!!

the edge of the world
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