On 02/17/2011 03:00 AM, Suntot wrote:

Well, I am new at this. Not even sure if what I am attempting is possible. I am trying to change a specific color in an image. If I use 'color selection' the edges don't change color. So I am trying to use color to alpha... But, when I select by color, it seems to select all similar color in the area, thus when I add a new layer it does the change the color I wanted to change, but it also changes the rest of the image with a similar color tone. What can I do to precisely select a specific color or portion of an image with color to alpha?

Color-to-alpha only applies to the selection, so you can restrict its effects by doing a selection first. For instance to remove a background, use the wand to get a rough selection of the background, grow the selection by a couple of pixels so that it includes the edges of the foreground, and perform color-to-alpha.

On 02/17/2011 03:00 AM, Suntot wrote:

Well, I am new at this. Not even sure if what I am attempting is possible. I am trying to change a specific color in an image. If I use 'color selection' the edges don't change color. So I am trying to use color to alpha... But, when I select by color, it seems to select all similar color in the area, thus when I add a new layer it does the change the color I wanted to change, but it also changes the rest of the image with a similar color tone. What can I do to precisely select a specific color or portion of an image with color to alpha?

Color-to-alpha only applies to the selection, so you can restrict its effects by doing a selection first. For instance to remove a background,
use the wand to get a rough selection of the background, grow the selection by a couple of pixels so that it includes the edges of the foreground, and perform color-to-alpha.

I tried doing a selection but since both colors are similar it selects all. Changed selection thresholds and it still doesn't work. Here is what I am trying to change:
http://www.weddingclipart.com/wca/edittemplate.do?template=218069

I am trying to change the colors of the scrolls on the wedding invitation. The dark blue into a red, the lighter into a black. Yet I can't seem to get it to work flawlessly. Please help. thanks

Use Colors->Threshold. You can then make an image like http://members.pcug.org.au/~rcook/images/threshold.png

Then do what you want with it. Just note that the scrolls are mirrors and reflection of one basic element, so you should be able to reconstruct easily

On 2011-02-17 17:24, Suntot wrote:

On 02/17/2011 03:00 AM, Suntot wrote:

Well, I am new at this. Not even sure if what I am attempting is possible. I am trying to change a specific color in an image. If I use 'color selection' the edges don't change color. So I am trying to use color to alpha... But, when I select by color, it seems to select all similar color in the area, thus when I add a new layer it does the change the color I wanted to change, but it also changes the rest of the image with a similar color tone. What can I do to precisely select a specific color or portion of an image with color to alpha?

Color-to-alpha only applies to the selection, so you can restrict its effects by doing a selection first. For instance to remove a background, use the wand to get a rough selection of the background, grow the selection by a couple of pixels so that it includes the edges of the foreground, and perform color-to-alpha.

I tried doing a selection but since both colors are similar it selects all. Changed selection thresholds and it still doesn't work. Here is what I am trying to change:http://www.weddingclipart.com/wca/edittemplate.do?template=218069

I am trying to change the colors of the scrolls on the wedding invitation. The dark blue into a red, the lighter into a black. Yet I can't seem to get it to work flawlessly. Please help. thanks

I got pretty good results by first selecting white, cutting that, pasting to a new layer, then selecting the light-blue, cutting that and pasting to a new layer and finally selecting dark-blue, cutting and pasting to new layer.
see http://screencast.com/t/jb44OAkIOywh

It could probably be done with fewer layers than I used ....

On 2/17/2011 11:24 PM, Suntot wrote:

On 02/17/2011 03:00 AM, Suntot wrote:

Well, I am new at this. Not even sure if what I am attempting is possible. I am trying to change a specific color in an image. If I use 'color selection' the edges don't change color. So I am trying to use color to alpha... But, when I select by color, it seems to select all similar color in the area, thus when I add a new layer it does the change the color I wanted to change, but it also changes the rest of the image with a similar color tone. What can I do to precisely select a specific color or portion of an image with color to alpha?

Color-to-alpha only applies to the selection, so you can restrict its effects by doing a selection first. For instance to remove a background, use the wand to get a rough selection of the background, grow the selection by a couple of pixels so that it includes the edges of the foreground, and perform color-to-alpha.

I tried doing a selection but since both colors are similar it selects all. Changed selection thresholds and it still doesn't work. Here is what I am trying to change: http://www.weddingclipart.com/wca/edittemplate.do?template=218069

I am trying to change the colors of the scrolls on the wedding invitation. The dark blue into a red, the lighter into a black. Yet I can't seem to get it to work flawlessly. Please help. thanks

I would use Select by Color tool, and adjust threshold in the Tool Options Menu.

Then bucket fill.

Abel

On 02/17/2011 11:24 PM, Suntot wrote

On 02/17/2011 03:00 AM, Suntot wrote:

Well, I am new at this. Not even sure if what I am attempting is possible. I am trying to change a specific color in an image. If I use 'color selection' the edges don't change color. So I am trying to use color to alpha... But, when I select by color, it seems to select all similar color in the area, thus when I add a new layer it does the change the color I wanted to change, but it also changes the rest of the image with a similar color tone. What can I do to precisely select a specific color or portion of an image with color to alpha?

Color-to-alpha only applies to the selection, so you can restrict its effects by doing a selection first. For instance to remove a background, use the wand to get a rough selection of the background, grow the selection by a couple of pixels so that it includes the edges of the foreground, and perform color-to-alpha.

I tried doing a selection but since both colors are similar it selects all. Changed selection thresholds and it still doesn't work. Here is what I am trying to change: http://www.weddingclipart.com/wca/edittemplate.do?template=218069

I am trying to change the colors of the scrolls on the wedding invitation. The dark blue into a red, the lighter into a black. Yet I can't seem to get it to work flawlessly. Please help. thanks

Some more thoughts on this... in my humble opinion, you cannot achieve a good-looking result if you change the anti-aliasing, and unfortunately all methods suggested so far alter it to some extent.

1) both parts of the clip art use the same hue, so they cannot be distinguished, in particular:

2) the anti-aliasing of the dark part on the white background uses colors found in the light one, and colors also used for the anti-aliasing of the light one

3) the anti-aliasing where light and dark intersect creates some intermediate colors very difficult to sort out

So a perfect cut will not be achieved without a lot of manual intervention.

However, the color of the whole clipart can be changed without adding aliasing by painting it over with a brush in "color" or "hue" mode (these modes won't affect the background) so you can change it to red tones fairly easily. Making the light one black will not work, because this will also affect the anti-aliasing pixels.Your best bet is to darken the dark one using the levels or curves tools, but you can't push it very far because this creates a light border around it (those $£à# pixels that are in the tone ranges of the light part...) (in other words you'll have to darken both parts if you want a very dark dark).

Conceal the trickery by flipping the clipart vertically :-)

Unless someone has a better solution?

-- Bertrand

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On 02/17/2011 11:24 PM, Suntot wrote

On 02/17/2011 03:00 AM, Suntot wrote:

Well, I am new at this. Not even sure if what I am attempting is possible. I am trying to change a specific color in an image. If I use 'color selection' the edges don't change color. So I am trying to use color to alpha... But, when I select by color, it seems to select all similar color in the area, thus when I add a new layer it does the change the color I wanted to change, but it also changes the rest of the image with a similar color tone. What can I do to precisely select a specific color or portion of an image with color to alpha?

Color-to-alpha only applies to the selection, so you can restrict its effects by doing a selection first. For instance to remove a background, use the wand to get a rough selection of the background, grow the selection by a couple of pixels so that it includes the edges of the foreground, and perform color-to-alpha.

I tried doing a selection but since both colors are similar it selects all. Changed selection thresholds and it still doesn't work. Here is what I am trying to change: http://www.weddingclipart.com/wca/edittemplate.do?template=218069

I am trying to change the colors of the scrolls on the wedding invitation. The dark blue into a red, the lighter into a black. Yet I can't seem to get it to work flawlessly. Please help. thanks

------big snip --------

Conceal the trickery by flipping the clipart vertically :-)

Unless someone has a better solution?

--
Bertrand

You can get a 'reasonable' result in Gimp. The colours actually select quite well and I found painting over with a large brush better than a bucket fill. Still those annoying pixels around the dark blue area spoil it.

A better solution?

Best results by far were with inkscape so maybe OP should consult the inkscape people. my attempt here http://imgur.com/UPWO2

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