Random Faces

This application goes through the files in the elements folder for a given artist and picks out one of each for every element of a face.

• eyes
• nose
• ears
• mouth
• chin
• hair
• extra (only 10% of all faces)

We also want to allow filtering by type.

• woman
• man
• elf
• dwarf

We're depending on a simple file name format: element_type_stuff.png, such as ears_elf_2.png. Each of these is a component of a particular face.

If we're requesting an element of a particular type and no such element exists, we'll take any element with type "all". Thus, if we're going to request elf ears, we'll get ears_elf_2.png. If we request dwarf ears and there are no special dwarf ears, we might get ears_all_1.png.

If we're don't determine a type, this is equivalent to asking for the "all" type. We might get ears_all_1.png but we won't get ears_elf_2.png.

This results in a problem when adding a type when there was none. At first, we just had hair_all_*.png. Then we decided that here was a hairdo for a woman and created hair_woman_3.png. From now on, the "all" type will no longer be considered for women. You could use a symbolic link called hair_woman_1.png for hair_all_1.png or you could rename hair_all_1.png to hair_all_woman_1.png`.

Adding Elements

Check out How to Draw a Face or a similar resource.

1. Print out a copy of the empty PDF with those egg-heads. Do not scale to fit! Use a scale of 100%. This PDF has some helping guidelines to make sure all the elements are more or less in the right place. The smaller horizontal lines are for the tip of the nose and the bottom of the mouth. See the example.

2. Use a blue fountain pen to draw a row of eyes, a row of noses, a row of mouths (maybe with mustaches), a row of hair (maybe with hats), and a row of ears or chins (maybe with beards). Or just draw sheet with just one element each. Fifty components (two sheets) per element seems to be a good starting point. If you're happy with dedicating your sheets to the public domain, then you can send your sheets to Alex Schroeder right away. Alex will do the rest.

3. Scan the image and crop it using The Gimp or whatever else you feel comfortable with. Cropping is important. The result must be an image 2250 pixels wide and 3000 pixels high. Rescale the image if necessary. Check out the examples on Flickr.

4. Clean up the image using ImageMagick and the following command line: convert -blur 0x1 +dither -remap tintenblau.png scan1.jpg source1.png – this forces the image to use the Tintenblau Palette (and loses the grid). We're also moving from JPG (which is what your scanner probably produced) to PNG. As for transparency: If your PNG file has transparency (an alpha channel), then it will work as intended. If you don't (because you're converting a JPG to a PNG as you did just now) then white is considered to be transparent when merging the various elements.

5. Cut the image into elements using cutter.pl. It cuts the scan into 5 × 5 images of 450 × 600 pixels each and labels them by row. You'd invoke it as follows: perl helpers/cutter.pl source1.png alex eyes_all nose_all mouth_all hair_all chin_all or perl helpers/cutter.pl source2.png alex eyes_all nose_all mouth_all hair_all ears_all. In other words: First is the source image, then the artist name, and then you provide the element for every row. If the remaining rows are all the same element, you don't need to repeat it. Thus, if you've drawn a sheet full of eyes, just use perl helpers/cutter.pl source4.png alex eyes_all and you're good. Make sure you use _all in the filename. That's how the system knows the face element can be used for all types of faces.

6. If you think that some of your samples are specific to a particular phenotype, add the type to the filename. If you have a beard, for example, rename it from chin_all_1.png to chin_man_1.png or if you have ears that are fit for elves only, rename it from ears_all_2.png to ears_elf_2.png.

Dependencies

The CGI script depends on Mojolicious (perhaps this is too old: sudo apt-get install libmojolicious-perl – I used cpan Mojolicious instead). Cutter depends on GD (sudo apt-get install libgd-gd2-perl). The clean up instructions depend on ImageMagick (sudo apt-get install imagemagick).

Installation

You can simply install it as a CGI script on your web server.

If you want to edit images using the script ("Face Debugging"), you'll need to add accounts to the config file. You'll have to create this file. The file must be called face.conf and it must reside in the same directory as face.pl, providing usernames and passwords. Every artist can have an account.

Session information is stored in an encrypted cookie. The encryption for the cookie also depends on a secret, so you should also provide a secret with which the cookie will be encrypted.

Here's an example for the config file, face.conf:

{
  secret => '*a random string*',
  users => {
    'alex' => '*secret*',
    'berta' => '*secret*',
  },
}

As the script is a Mojolicious app, there are many other ways to deploy it. There is a Cookbook with a section on deployment. The following is a quick summary.

This runs the script as a server on localhost:3000:

perl face.pl daemon

This runs the script as a server on localhost:3000 and reloads it every time you change it:

morbo face.pl

This runs the script as a server on port 8080, writing a pid file:

hypnotoad face.pl

Whenever you repeat this hypnotoad command, the server will be restarted. There's no need to kill it.

You can configure hypnotoad to listen on a different port by adding an additional item to the config file:

{
  hypnotoad => {listen => ['http://*:8082'],},
  secret => '*a random string*',
  users => {
    'alex' => '*secret*',
    'berta' => '*secret*',
  },
}

Finding and fixing misaligned elements: the easy way

If you're an artist and you're logged in, the main menu will have a new item: Face Debugging. Follow the link, pick an element type, view the gallery, pick an element that is misaligned and klick it. You're now on the Element Edit page. Click on the upper half of the image to move the element up by ten pixels, click on the lower half of the image to move the element down by ten pixels.

Finding and fixing elements: the hard way

I start the script using morbo and visit the gallery URLs with the debug parameter set to 1:

http://localhost:3000/gallery/man?debug=1

Then I just reload until I find a face where things are misaligned. I right-click and pick "Show Graphic". This leads me to a link like the following:

http://localhost:3000/face/alex/empty_all.png,eyes_all_72.png,mouth_all_49.png,chin_man_30.png,ears_all_5.png,nose_all_20.png,hair_man_21.png

This shows me which elements were used to create the face I'm looking at.

If you've found just a single misaligned element, you can change it in place by providing the same file name twice to ImageMagick:

convert -page +0+10 -background white -flatten elements/alex/chin_man_30.png elements/alex/chin_man_30.png

If it turns out that you scanned a bunch of elements and they're all shifted by some amount, you can use the shell to make your life easier. Here is what I used to shift some old eye elements down by 35 pixels:

for n in `seq 34`; do
  convert -page +0+35 -background white -flatten elements/alex/eyes_all_$n.png eyes_all_$n.png
done

This will create copies in your current directory. If you're happy, move them back into the elements folder.

If you need help figuring out by how much you might want to shift images, you can use top.pl and bottom.pl. They cound how many white lines there are at the top and at the bottom, respectively.

Example usage:

perl helpers/top.pl elements/alex/eyes_all_*

Alternative look

For my images I enforced a blue color map because I was doing my drawings using a blue fountain pen. This is the command line I used in my example above: convert -blur 0x1 +dither -remap tintenblau.png scan1.jpg source1.png

If you do your drawings using a pencil, you might want to keep the pencil look. I'll suggest the following command line: convert -blur 0x1 +dither -level 30%,80% scan1.jpg source1.png. Like in the previous example, I used a 1px blur and then I adjusted levels: anything below 30% is black and anything above 80% is white. It looks OK. No trace of the helping lines left and it keeps the pencil gray.

If you do your drawings using a pencil but you'd like to give it an inked look, you migh want to increase the percentage for the black level. I'll suggest the following comand line: convert -blur 0x1 +dither -level 50%,80% -grayscale rec709luma scan1.jpg source1.png. Now anything below 50% is black. I also converted it to grayscale at the end because the very light pixles seemed to have random colors.

Transparency and Opacity

Sometimes you want white to be opaque. You would like to have hair that covers a face, or a hat that covers the face. One solution is to use nearly white. It's hard to work with, however. When you open the element in Gimp, you can't tell which sectinos are white and which ones are nearly white. In this case, use transparency. In Gimp:

1. Layer → Transparency → Add Alpha Channel
2. Choose the magic wand using u
3. Set the tool options to no antialiasing and use a threshold of 0.0
4. Select the white background with a click and cut it away (Edit → Cut)
5. Any remaining white will remain opaque, which is probably OK

Now you're ready to change some light colors to white, if you want to.

There's a little helper script to identify transparent images, if you need it.

Example usage:

helpers/transparent.pl elements/rorschachhamster/*.png