Re: [Gimp-user] dotted areas, how to erase (or change)

[Steve Kinney <admin pilobilus net>]

On 02/28/2012 12:52 AM, mamboze wrote:
> I've got a problem editing an image with a dotted background in it. By 'dotted', I mean an array of small 
> evenly spaced black dots on a white background. 
>
> I've tried the fuzzy select tool which kind of works. It fills in the white space with the color I want but 
> leaves the dots untouched. I want to get rid of the dots.
>
> The image has a lot of rectangles containing text (these are not dotted) on this dotted background so using 
> the select tool would be a real chore.

Hey Mamboze,

Try this:

* Make a new layer, fill it with your desired background color, and
move it down so it is under your original image layer.

(This is done in the Layers tab of your dock window.)

* Select the original image layer, right click on it, and Add Layer
Mask.  Make the mask white - "full opacity".

* Open up your color selector (add set a light gray color - about
50% gray.

* Click on the layer mask to select it, then drag & drop to the main
image window to fill the mask with gray.

* Back in the color selector, get some pure white selected.

* Turn on your rectangular select tool.  Start using that to select
your rectangles with text in the main image window, drag and drop to
fill them with white.

(This will bring your rectangles back to their original appearance
by restoring the mask's effect to 100% opacity in those areas.)

*  All done?  Use the "magic wand" or the "select by color" tool to
select the gray in your layer mask.

*  Back in the color selector, get some 100% black going, drag and
drop to fill the selected gray area in your mask with black.

That will make your dots vanish entirely, leaving the layer below
fully visible.  You can use the select tools with drag and drop, or
any of the painting tools, to correct any errors in your mask by
adding white (make parts of the layer visible) or black (making
parts of the layer invisible).

If you use the GIMP long enough, you will start to think of an image
as a stack of layers, and using masks will (almost!) completely
replace the "erase" tool. 

Another neat thing to play with is to make a copy of a layer, apply
a filter that you want to use on some but not all parts of the
finished image, and make the altered layer transparent by adding a
black layer mask.  Then, painting in the image window with white
will enable you to "paint the image with" the filter(s) you applied
to the new layer.

:o)

Steve