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Modify alpha transparency of selected pixels?

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Modify alpha transparency of selected pixels? Jeremy Morton 25 Jun 17:13
  Modify alpha transparency of selected pixels? Mikael Magnusson 25 Jun 17:49
   Modify alpha transparency of selected pixels? Jeremy Morton 25 Jun 18:13
  Modify alpha transparency of selected pixels? Rob Antonishen 25 Jun 18:26
Modify alpha transparency of selected pixels? Jeremy Morton 25 Jun 17:53
  Modify alpha transparency of selected pixels? Tobias Ellinghaus 25 Jun 18:09
Jeremy Morton
2011-06-25 17:13:48 UTC (over 13 years ago)

Modify alpha transparency of selected pixels?

Hi all,

Several times now it has occurred to me that it would be useful to be able to modify alpha transparency of pixels selected. I can already modify their colour in numerous ways (brightness/contrast, colorize, invert, etc.) so why not alpha transparency? Right now, the way you have to do it is clunky. You select the pixels, 'cut' them, paste them onto a new layer, modify that layer's transparency, and merge it down into the original layer again. Why not add some functions to increase selected pixels' opacity, reduce it, or set them to a given value (0-255)?

Mikael Magnusson
2011-06-25 17:49:09 UTC (over 13 years ago)

Modify alpha transparency of selected pixels?

On 25 June 2011 19:13, Jeremy Morton wrote:

Hi all,

Several times now it has occurred to me that it would be useful to be able to modify alpha transparency of pixels selected. I can already modify their colour in numerous ways (brightness/contrast, colorize, invert, etc.) so why not alpha transparency? Right now, the way you have to do it is clunky. You select the pixels, 'cut' them, paste them onto a new layer, modify that layer's transparency, and merge it down into the original layer again. Why not add some functions to increase selected pixels' opacity, reduce it, or set them to a given value (0-255)?

Add Layer Mask -> transfer alpha channel

Jeremy Morton
2011-06-25 17:53:05 UTC (over 13 years ago)

Modify alpha transparency of selected pixels?

On 25/06/2011 18:41, Fabio Gonzalez wrote:

2011/6/25 Jeremy Morton >

Hi all,

Several times now it has occurred to me that it would be useful to be able to modify alpha transparency of pixels selected. I can already modify their colour in numerous ways (brightness/contrast, colorize, invert, etc.) so why not alpha transparency? Right now, the way you have to do it is clunky. You select the pixels, 'cut' them, paste them onto a new layer, modify that layer's transparency, and merge it down into the original layer again. Why not add some functions to increase selected pixels' opacity, reduce it, or set them to a given value (0-255)?

--
Best regards,
Jeremy Morton (Jez)
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you can use masks on selected pixels

I don't see how that lets you actually set the pixel's alpha value, though. You have to mess around with the mask getting its pixels just the right value to make the pixel's alpha value right, which is probably harder than using the cut/paste/merge method I mentioned previously. What I really want to be able to do is enter a number and set the selected pixels' alpha transparency to that number.

Tobias Ellinghaus
2011-06-25 18:09:43 UTC (over 13 years ago)

Modify alpha transparency of selected pixels?

Am Samstag, 25. Juni 2011 schrub Jeremy Morton:

[...]

you can use masks on selected pixels

I don't see how that lets you actually set the pixel's alpha value, though. You have to mess around with the mask getting its pixels just the right value to make the pixel's alpha value right, which is probably harder than using the cut/paste/merge method I mentioned previously. What I really want to be able to do is enter a number and set the selected pixels' alpha transparency to that number.

You can enter that number in the colour dialog and fill the mask with the resulting colour. Since you already selected the pixels the mask will only be changed for those.

Jeremy Morton
2011-06-25 18:13:49 UTC (over 13 years ago)

Modify alpha transparency of selected pixels?

Ah thanks... that works quite nicely.

Rob Antonishen
2011-06-25 18:26:53 UTC (over 13 years ago)

Modify alpha transparency of selected pixels?

on Sat, Jun 25, 2011 at 1:13 PM, Jeremy Morton wrote:

Hi all,

Several times now it has occurred to me that it would be useful to be able to modify alpha transparency of pixels selected. I can already modify their colour in numerous ways (brightness/contrast, colorize, invert, etc.) so why not alpha transparency? Right now, the way you have to do it is clunky. You select the pixels, 'cut' them, paste them onto a new layer, modify that layer's transparency, and merge it down into the original layer again. Why not add some functions to increase selected pixels' opacity, reduce it, or set them to a given value (0-255)?

You can also use the curves/levels dialogs on the alpha channel directly to accomplish all those tasks.

-Rob A>