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Scribus => Raster and Vector Graphics => Bitmap Images => Topic started by: robertsharp on June 25, 2012, 01:37:04 PM

Title: Changing the colour of a Grayscale or Bitmap image
Post by: robertsharp on June 25, 2012, 01:37:04 PM
Hi folks,

I've only just started using Scribus, having had some experience with both InDesign and QuarkXpress in the past.

I am trying to perform what I think is a simple task, but cannot for the life of me see how to do it.  I want to apply a colour of my choice to a black and white bitmap tiff image.

I have imported a graphic image as a black and white bitmap.  It appears in the layout as a black image on a white background, as one would expect.

I want to apply a custom colour to this graphic.  I highlight the image, then go to Properties > Colors
Then I click the 'Edit Fill Color Properties' button.
Then I click on the colour I want, from the swatch.

At this point, I would expect to see the graphic change to the colour I've chosen.  But nothing happens.  If I delete the image from the frame, I see that colour filling the empty text box.    The same effect happens when I try Grayscale images.  Overall, it is as if the images are being treated as RGB with colour information included.

The exact same effect happens in InDesign when you accidentally import an RGB or CMYK file, thinking its Grayscale or Bitmap.  So please rest assured I have checked that the files I am importing are Bitmap TIFFs, not RGB, etc.

I've done an extensive search of the forums and the web and don't see any HOWTO or explanation of how to achieve what I think is a trivially simple task.  I apologise if I am missing something obvious, but it would be great to get some pointers on how to get this done.

With many thanks...
Title: Re: Changing the colour of a Grayscale or Bitmap image
Post by: a.l.e on June 26, 2012, 06:46:06 AM
hi robert,

the fill color is for the frame and not the image.
in this getting you're getting a colored frame background, which you probably don't see, because your image fills the whoe frame.

the best choice to apply the effect you're looking for is to use a bitmap editor like the gimp...

... but if you really want to apply a coloring filter, select your image and go to item > effects... you will find some neat things in there!

have fun
a.l.e
Title: Re: Changing the colour of a Grayscale or Bitmap image
Post by: brownie on May 22, 2024, 03:35:42 PM
Hi,

I am a quite experienced designer (QuarkXpress and Indesign) and have the same problem as Robert. Unfortunately the only answer didn't solve the issue how to change the color of a bitmap.

A bitmap should also not be displayed with a background color, cause a bitmap is just a map of bits (there is no "black and white", there is only "black"). So how can a bitmap be displayed without a background color (cause it has none) and used what it is for, f. e. for logos to choose a special color and lay it on a photo without having it surrounded by a frame that a bitmap doesn't have?

Your answer will be highly appreciated!
Title: Re: Changing the colour of a Grayscale or Bitmap image
Post by: PatJr on May 22, 2024, 03:44:42 PM
Can you post up a sample file of an image similar to what you want to work with?

gimp can remove a color and set it to transparent, just save it as a png so the transparency is preserved

scribus has some image manipulation tools
select the image frame then
Item>Image>Image Effects   or Crl-E
Title: Re: Changing the colour of a Grayscale or Bitmap image
Post by: brownie on May 22, 2024, 03:56:29 PM
Ok, I just found out that one can change the color of the bitmap in the effects section (bottom of the pop-up window). Great so far.

But there is still the issue left that the bitmap has a white background (the frame has no background). How can I remove the background of the bitmap (which it doesn't have)? When I use the same bitmap in Indesign, it doesn't have a white background.

Thx PatJr for your help, that was posted while I was writing this.

So what you mean is that Scribus cannot handel a bitmap file for what it is? I have to use a png-file instead?
Title: Re: Changing the colour of a Grayscale or Bitmap image
Post by: brownie on May 22, 2024, 04:10:03 PM
Wow PatJr, I tried your solution and it worked to place the logo without background.

Thank you very much so far!

But then I couldn't change the color of the logo anymore. The SCRIBUS-effects do not work with PNG files.

My workaround:
I set the background transparent in GIMP and also changed the color of the logo in GIMP and saved the final logo version as a png and then placed it in SCRIBUS. Now the logo is shown without background. It is still poor that I can't change the logo color easily in SCRIBUS.

Scribus should work on that issue imho. It definitely should be able to handle bitmap files.
Title: Re: Changing the colour of a Grayscale or Bitmap image
Post by: Nermander on May 22, 2024, 04:50:04 PM
A "normal" RGB bitmap file contains colors ranging from black (0,0,0) to white (255,255,255), so there is always a "background".

You need a bitmap format with transparency to get rid of any background.
Title: Re: Changing the colour of a Grayscale or Bitmap image
Post by: a.l.e on May 22, 2024, 05:36:46 PM
... and if you plan to rely on that transparency to make into the pdf and then on paper:

- you need to use a pdf version that support transparencies,
- and make sure that your printer (print shop...) honors the transparencies in the pdf.

... because scribus won't flatten the transparencies for you.