Storyboard Artwork Project/Creating Tux Paint Stamps

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These lessons are ready for a test drive.

How to create Tux Paint stamps for the Storyboard Artwork Project

What are stamps in Tux Paint?

Stamps are pictures with a mask.
Each stamp has a mask which crops the picture so stamps can be any shape.
Note: A mask is also known as an Alpha Channel.
In this scene, you see two men walking together. It looks natural and real. Yet this scene was made from two stamps with only two clicks on the screen.
It took only ten seconds to create this entire scene. Stamps are an extremely effective drawing tool.
An example of a stamp

Four channels in one PNG picture

A PNG picture has four channels:

  • A red image
  • A green image
  • A blue image
  • A mask image

In case you are wondering why they are five images for picture with four channels, the first image at the top is a quick look at all the RGB channels put together as a complete color picture.

This top image is not a channel but because the color picture is so useful, it is included in the list of channels with a channel number of "tilde".

The color channels of the stamp
The RGB channels

Here are the color channels all together for a stamp.

When you combine the red, green and blue channels, you get a color picture.

In this case, the picture is 400 pixels tall and 200 pixels wide. We need pictures which are over 500 pixels tall. For technical reasons, we prefer that you make your stamps 1000 pixels tall.

The alpha channel of the stamp
The mask channel

Here is what an alpha channel looks like. This is a gray image which is almost entirely black and white. Only at the edge of the fireman are there gray pixels to feather the mask.

In the white part of the mask, the image becomes part of the stamp. Where the mask is black, the image is not included in the stamp.

A Great Moment In History: The almost true story of "Alpha"
The naming of the "Alpha Channel".

Here is the scientific logic behind the fourth image in a PNG picture.

Each pixel of a PNG picture (a color picture for the computer) is described by 8 binary bits of red, 8 binary bits of blue and 8 binary bits of green. Since 32 binary bits is a very convienent word size for most computers (i.e., 4 times 8 binary bits), scientists said, "Let's use all 32 bits for a single pixel since this is very efficient. And in the 8 bits that are not being used, let's add a gray image which explains how transparent the RGB image is."

Everyone agreed that this was a wonderful idea.

But then someone said, "But what should we call this gray image since it is neither "red" nor "blue" nor "green"? We need a fancier name than "transparency" because that would be too simple.

One scientist, whose name was "Fred" said he wanted to call it "Fred". Then another wanted to call it "Burt" Then another wanted to call it "Kate" and finally one wanted to call it "Christine" for the famous rocket scientist, Christine Latter of Boise, Idaho.

Sadly, being scientists, they could not agree. So finally they simply called it by the totally ridiculous name of "Alpha" since that was the first letter of the Geek alphabet and, therefore, the only name they could agree on.

And at the same time, they also decided that saying "red image" and "blue image" and "Alpha image" was not digified enough. So they decided to call the images "Channels" which sounds more scientific. (They did not want anyone to confuse them for English majors.)

Where are stamps in Tux Paint?

Things to do

Locate the stamps in Tux Paint and view them them with your photo editing software like Photoshop or The Gimp to see the four channels, specially the Alpha chennel which is the mask. Photoshop 4 or later will do this but I do not believe that Photoshop Elements can view channels. In The Gimp the mask is displayed besides the layer.
Tux Paint works on many different computers and hand held devices. Therefore, finding the stamps is not always easy.
On the Macintosh, you cannot simply search for "Stamps" because the search engine in Mac OS X does not search inside an application. If you use the new Macintosh (Mac OS X), an application is not just a program. Rather an application is actually an invisible folder which contains all the elements of the application. Using the Control key allows you to see the contents of the application folder so you can find the stamp folder in the resource folder.
What size are stamps?
How tall?

Stamps can be any size. Stamps are enlarged automatically in Tux Paint. However, there are some limitations to Tux Paint.

The largest setting in Tux Paint enlarges the picture to 95% of the full height of the Tux Paint's current screen size. But be aware that when Tux Paint automatically scales up a picture, it becomes jagged if the original is not large enough.

For this project, we will use a Tux Paint screen which is 600 by 800. This produces a painting which is 472 pixels tall. Therefore, the stamps should be at least 472 pixels tall to get full resolution for large stamps.

Upper half the the body

Besides full size images, we need the same figures showing only the upper half of the body. Tux Paint cannot crop more than half of the picture. Therefore, Tux Paint cannot create head shots from full sized images. Therefore, we also need you to create a second set of stamps by cropping your artwork to the upper half of the body. (We can do this for you if you wish.)