If you want to
use your own pictures of leaves on your tree you first
need to make a leaf texture file.
In each colour
picture there are usually three channels one each for
red, green and blue. When these three channels are combined the colour
picture is created. Little Stick needs to know where the leaf exists
and where it does not and for this it uses an additional channel called
an Alpha Channel. The alpha channel is just like a red, green or blue
channel but stands for transparency. Where the alpha channel is black,
the picture is transparent. Where the alpha channel is white, the
picture is opaque. Finally where the alpha channel is grey, the picture
is semi transparent. The best way to understand alpha channels is to
experiment with Photoshop or the GIMP.
To examine a
typical alpha channel choose "Save Picture" from the File
menu and check the box "Export alpha only". When you click "OK", the
picture saved will be the alpha layer of the current picture.
2. Use the view
controls in the View
palette to
move the tree such that the trunk starts in the middle
and at the bottom of the picture.
3. Select "Save
Picture" from the File menu.
4. Choose a name
for the picture and select TIFF for the picture format.
5. Choose another tree to draw,
one where you can see individual leaves clearly such as the Flower.
(Fantasy, Others)
6. Use the view
controls in the View
palette to
move the tree such that a leaf is clearly visible.
7. Click on the Load
Leaf texture
button and choose the tree picture saved earlier.
Using Photoshop
Photoshop is the
leading commercial image editor.
1. Take a colour
photograph of a leaf against a white background.
2. Open the
picture in Photoshop.
3. In the
Layers, Channels and Paths tool box, click on the Channels tab and then
the Create new channel
button.
4. Click on the RGB channel to correctly display the leaf again.
4. Use the magic
wand tool to select the white area around the leaf. (Click on the white
area)
5. Invert the
selection to select the leaf rather than the area around it. (Command +
Shift +I)
5. Tidy up the
selection with the lasso tool.
6. Click on the
new channel that you have just created. The area of the leaf should
still be selected but the picture will be black.
7. Press delete.
The new layer should be white where the leaf exists
and black where it does not.
8. Select
"Canvas Size" from the Image menu. Choose the dimensions of the canvas
to be square rather than rectangular.
9. Select all.
(Command + A)
10. Select "Free
Transform" from the Edit Menu, (Command + T), and move the picture so
that the stem of the leaf exits the picture at the bottom and middle.
9. Save the
picture in TIFF format with the Alpha Channels box checked.
This picture
file is now ready to be used in Little Stick.
Using the GIMP
The GIMP is the
leading free image editor. These instructions apply to GIMP v2.2.10,
but you should be able to use them with other versions.
1. Take a colour
photograph of a leaf.
2. Open the
picture in GIMP.
3. Select the
Layer menu, then Transparency, then Add Alpha Channel.
4. Choose the
Select contiguous regions (magic
wand) tool and click on a background area.
5. Tidy up the
selection with the Select hand-drawn regions (lasso) tool.
6. Select Clear
from the Edit menu.
7. Select Canvas
Size from the Image menu.
8. In the Canvas
Size window, click on the chain so that it changes from linked to
unlinked .
9. If the number
in the Width box is the smallest, change it to be the same as the
number in the Height box. If the number in the Height box is the
smallest, change it to be the same as the number in the Width box.
10. Click the Center button.
11. Click the Resize button.
12. Choose All from the Select menu.
13. Choose the Move Layer and Selections tool. Click and drag the
picture so that the leaf starts in the middle of the picture and at the
bottom.
14. Choose Save As from the File menu. Type in filename.tif. The .tif on the end
sets the image type to TIFF automatically.
15. Click Save and then Export.
16. I suggest choosing LZW compression from the save window. This
compresses the image and is very compatible with other programs that
read TIFF images. Click OK.
This picture
file is now ready to be used in Little Stick.
to
unlinked 
.