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Image diffenernt after saving

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Image diffenernt after saving Silt 21 May 21:18
  Image diffenernt after saving Richard 22 May 16:30
   Image diffenernt after saving Silt 23 May 06:08
    Image diffenernt after saving Richard 24 May 04:02
     Image diffenernt after saving Silt 24 May 06:41
      Image diffenernt after saving Richard 25 May 01:01
2016-05-21 21:18:22 UTC (over 8 years ago)
postings
3

Image diffenernt after saving

I want to make a Piviot animation with sprites, what means I took a picture of myself, and cut the bodyparts out (legs, arms, head, chest) and wanted to put them together again, but the image slightly changed, what destroyed the tansperency (see image) Before I saved the background had the same color, but after saving not anymore... Thank you!

Richard
2016-05-22 16:30:03 UTC (over 8 years ago)

Image diffenernt after saving

Looks like a classic case of "residual" alpha data (areas with less-than-full transparency) to me. This is something you typically end up dealing with any time you use an automated tool to 'cut out' an image in GIMP because depending on what tools you're using to assemble your sprite later, they may or may not handle partial transparency properly.

What you should do (or at least what I'd do personally) is take the Eraser tool and start erasing around the vicinity of your object to ensure that the transparent areas around it really are 100% transparent.

Alternately, go to the Colors menu and select the "Levels..." option. On the dialog that pops up you will be a dropdown with a list of color channels in the image (red/green/blue). Select "Alpha" from the dropdown and notice the histogram that appears in the chart. Take the black end of the alpha range and drag it up the scale by a small amount -- this will wash out the alpha values of transparent areas to ensure that areas that look 100% transparent really ARE 100% transparent.

-- Stratadrake strata_ranger@hotmail.com
--------------------
Numbers may not lie, but neither do they tell the whole truth.

Date: Sat, 21 May 2016 23:18:22 +0200 From: forums@gimpusers.com
To: gimp-user-list@gnome.org
CC: notifications@gimpusers.com
Subject: [Gimp-user] Image diffenernt after saving

I want to make a Piviot animation with sprites, what means I took a picture of myself, and cut the bodyparts out (legs, arms, head, chest) and wanted to put them together again, but the image slightly changed, what destroyed the tansperency (see image)
Before I saved the background had the same color, but after saving not anymore...
Thank you!

Attachments:
* http://www.gimpusers.com/system/attachments/247/original/Unbenannt.PNG

-- Silt (via www.gimpusers.com/forums)
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List address: gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list

2016-05-23 06:08:19 UTC (over 8 years ago)
postings
3

Image diffenernt after saving

I forgot to say that, but it is not really tansparent, Privot takes the bottom right (or left, I'm not sure) pixel and makes all of this color tansparent. So in GIMP 2 it is white, and in Privot tansparent, with the bug as shown in the image. But yes I will try that with the eraser tool, thanks for your answer.

Looks like a classic case of "residual" alpha data (areas with less-than-full transparency) to me. This is something you typically end up dealing with any time you use an automated tool to 'cut out' an image in GIMP because depending on what tools you're using to assemble your sprite later, they may or may not handle partial transparency properly.

What you should do (or at least what I'd do personally) is take the Eraser tool and start erasing around the vicinity of your object to ensure that the transparent areas around it really are 100% transparent.

Alternately, go to the Colors menu and select the "Levels..." option. On the dialog that pops up you will be a dropdown with a list of color channels in the image (red/green/blue). Select "Alpha" from the dropdown and notice the histogram that appears in the chart. Take the black end of the alpha range and drag it up the scale by a small amount -- this will wash out the alpha values of transparent areas to ensure that areas that look 100% transparent really ARE 100% transparent.

-- Stratadrake
strata_ranger@hotmail.com
--------------------
Numbers may not lie, but neither do they tell the whole truth.

Richard
2016-05-24 04:02:43 UTC (over 8 years ago)

Image diffenernt after saving

Date: Mon, 23 May 2016 08:08:19 +0200 From: forums@gimpusers.com
To: gimp-user-list@gnome.org
CC: notifications@gimpusers.com
Subject: [Gimp-user] Image diffenernt after saving

I forgot to say that, but it is not really tansparent, Privot takes the bottom right (or left, I'm not sure) pixel and makes all of this color tansparent. So in GIMP 2 it is white, and in Privot tansparent, with the bug as shown in the image. But yes I will try that with the eraser tool, thanks for your answer.

Okay. Then the problem is that your background color isn't a solid white but actually several (subtly) different shades, and even a +/-1 difference in a pixel's RGB values may dictate whether Pivot treats it as opaque or transparent.

How to fix it remains largely the same in concept, but the execution will be slightly different. And there are several ways, depending on exactly what you want.

For example, take the Paintbrush (or Pencil tool) and pick a fairly hard-edged brush shape, set GIMP's foreground color to your desired background color, then start painting around the background spaces of your image. This will ensure that the background really IS a single solid RGB value and not a mix of hues or tints.

This can also be somewhat automated:

- Switch to the Fuzzy Select tool and on its tool options, specify a small threshold value (say, 8-16 range) and disable the antialiasing and feathering options. - Click somewhere in your desired background area. This will highlight all contiguous regions whose color is within the threshold of the pixel you clicked. - FIll the area with a solid color (e.g. Edit > Fill with FG/BG color, or Paint bucket tool with "fill whole selection" option set).

But automatic tools never yield a truly perfect solution -- you'll only get that from manual effort.

By the way, since you mentioned how Pivot uses a 'chroma key' system, I'd recommend picking a color that is obviously not a normal part of the image (e.g. a pure RGB primary or secondary) and painting the image's background with THAT. This will eliminate any ambiguity about which pixels are intended to be opaque or transparent in Pivot, because only your key color will be rendered transparent.

-- Stratadrake strata_ranger@hotmail.com
--------------------
Numbers may not lie, but neither do they tell the whole truth.

2016-05-24 06:41:52 UTC (over 8 years ago)
postings
3

Image diffenernt after saving

I used the normal pencil tool at the start and for some reason that didn't made everything white, but it messed up just at the border of the image. Might be because I changed it from .jep to .png but I'm not sure Now I just used the filling tool with slightly simmilar colors and it works fine now, just a bit trouble ahaed to change all these images slightly... Thanks for your help.

Okay. Then the problem is that your background color isn't a solid white but actually several (subtly) different shades, and even a +/-1 difference in a pixel's RGB values may dictate whether Pivot treats it as opaque or transparent.

How to fix it remains largely the same in concept, but the execution will be slightly different. And there are several ways, depending on exactly what you want.

For example, take the Paintbrush (or Pencil tool) and pick a fairly hard-edged brush shape, set GIMP's foreground color to your desired background color, then start painting around the background spaces of your image. This will ensure that the background really IS a single solid RGB value and not a mix of hues or tints.

This can also be somewhat automated:

- Switch to the Fuzzy Select tool and on its tool options, specify a small threshold value (say, 8-16 range) and disable the antialiasing and feathering options.
- Click somewhere in your desired background area. This will highlight all contiguous regions whose color is within the threshold of the pixel you clicked.
- FIll the area with a solid color (e.g. Edit > Fill with FG/BG color, or Paint bucket tool with "fill whole selection" option set).

But automatic tools never yield a truly perfect solution -- you'll only get that from manual effort.

By the way, since you mentioned how Pivot uses a 'chroma key' system, I'd recommend picking a color that is obviously not a normal part of the image (e.g. a pure RGB primary or secondary) and painting the image's background with THAT. This will eliminate any ambiguity about which pixels are intended to be opaque or transparent in Pivot, because only your key color will be rendered transparent.

-- Stratadrake strata_ranger@hotmail.com
--------------------
Numbers may not lie, but neither do they tell the whole truth.

Richard
2016-05-25 01:01:43 UTC (over 8 years ago)

Image diffenernt after saving

Date: Tue, 24 May 2016 08:41:52 +0200 From: forums@gimpusers.com
To: gimp-user-list@gnome.org
CC: notifications@gimpusers.com
Subject: [Gimp-user] Image diffenernt after saving

I used the normal pencil tool at the start and for some reason that didn't made everything white, but it messed up just at the border of the image. Might be because I changed it from .jep to .png but I'm not sure Now I just used the filling tool with slightly simmilar colors and it works fine now, just a bit trouble ahaed to change all these images slightly... Thanks for your help.

Hold the phone did you say .jpeg? You should definitely *not* be using JPEG for your sprite files because the lossy JPEG compression algorithm will definitely cause transparency problems in Pivot (depending on how sensitive Pivot is to the chroma key's RGB values. Check your Pivot documentation for any options related to this).

-- Stratadrake strata_ranger@hotmail.com
--------------------
Numbers may not lie, but neither do they tell the whole truth.