Properly replacing a colour in a simple bitmap

I have a low-res bitmap. It has a dark grey background with a plain white icon. The transitional pixels are various shades of grey.

I want to make the dark grey into a bright blue, leave the white white, and have the transitional pixels changed to maintain their respective "in between" values.

I do have Photoshop CS2 but I though Xara was more likely to be able to do this. Can anyone help?

Thanks :)

Xara Designer Pro X has a Color Select/Erase Tool that can do this, though to be honest, the results vary.

Aw I don't seem to have that tool in PGD6. Any other ways? Seems like this must be something people do all the time.

Thanks

Can we see the bitmap?

you can try mehdi eraser in the live effects

John made a quick tutorial here:

http://www.talkgraphics.com/showthre...547#post328547

Attachment 96785

:) and I want the dark grey to be 0050ef

Cheers

black and white is easy - to replace the white you give the bitmap a stained glass transparency put a colour rectangle behind select both and make a true colour bitmap copy

to replace black just invert the bitmap first

ah - your edit makes it a bit more complicated :)

Quote:

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Originally Posted by handrawn

ah - your edit makes it a bit more complicated :)

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Thanks, that solution works well :)

As you say though.... how on Earth do I tell Xara to use a specific blue? I've never seen such a bad colour selection dialogue. I can't even specify RGB values :/

ok

select the bitmap - click on white on the colour bar and select 'set contone dark colour' - then click on black on color line and select 'set contone light colour' - bitmap is now inverted

keep your bitmap selected and go to bitmap gallery and click on the original bitmap there and then the 'transp' button [transparency] - you will now have an object that is single colour and alpha - use the colour editor to set it to your grey value, and then put a white rectangle behind - select both and make bitmap copy

edit - ok you used the mehdi method :)

do you mean the colour editor in xara - you need the colour editor drop down menu [top right button on the editor] change colour model to RGB and you can enter hex

No I used your Stained Glass method. It worked well except that:

Xara kept screwing up the export because it couldn't flatten the transparency properly.
Xara wouldn't let me type in the colour I wanted to use.
When I used the colour sampler, Xara actually didn't quite match the colour correctly.
Xara couldn't easily invert the bitmap.
Xara wouldn't let me easily view the bitmap at 1:1

So I had to sample the opposite of the colour I wanted, put it as the background, then guesstimate where 1:1 was and use the Windows Snipping Tool.

All in all, Xara just fell a huge amount in my estimations, but I'm glad it could at least do the thing I wanted. Now my background is only 1 shade of blue off where it should be.

Thanks for your help :)

Ah good. Mission accomplished with the correct shade of yellow (later inverted in Photoshop).

Thanks :)

Looks like the comments got out of order :/

that is the downside of the stained glass method - if it's not 'pure' white/black you can get a 'cast' in the colour.... that's why it's called 'stained' glass I guess... I use a photoshop filter to get rid of white and black that works in xara [but you need photoshop installed]

the later versions of xara have improved in this respect

Have I missed something here?

I just loaded the image into XDPX.
Changed the dark contone to #0050ef

glad you got it sorted :)

Quote:

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Originally Posted by Rik

I just loaded the image into XDPX.
Changed the dark contone to #0050ef

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Oh that would be good. How do you do that?

Quote:

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Originally Posted by handrawn

...if it's not 'pure' white/black you can get a 'cast' in the colour....

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Yeah I used Photoshop first to make it black & white.

Quote:

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Originally Posted by M4R5

Oh that would be good. How do you do that?

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Open the Colour Editor.
Open the drop-down menu and select 'Dark Contone'
Enter the value required.

Hi Rik - no you are quite right of course for a case where the bitmap only includes two shades...contones even

Quote:

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Originally Posted by handrawn

Hi Rik - no you are quite right of course for a case where the bitmap only includes two shades...contones even

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Thanks. Steve.
I saw the image, and saw that there was an easy answer.

Is your link to John's post in your Post #5, the answer then?

Rik - my personal preferred solution for more than two shades is to set photoshop as my bitmap editor in xara options :D

but if you want to do it in xara then the mehdi does work quite well - sometimes the 'eraser genuine' [free from mehdi site] works better than the classic

be interesting to see how useful the new eraser feature is in this respect in version 9 [the version 8 colour select/erase is not as good as photoshop IMO]