STEP BY STEP TUTORIAL ON HOW TO CREATE GB-ALIKE IMAGES by stage7

Distributed under a Creative Commons license BY-NC



step01
Create your palette using your favourite simple image editor so you get
four grey tones, pure black (RGB 0,0,0), dark gray (85,85,85), light gray
(170,170,170) and white (255,255,255). We will export our palette from
this image in the next step.

step02
Open your photo editor and convert the previous image to 8-bit color so
we can extract a processed palette from it. As you can see, there are
four colours detected. Save your palette with your editor (the procedure
will vary from one program to another).

step02a
A close view on how a palette is saved with Corel Photo-Paint.

step03
Open the picture you are going to convert and make sure it is 160*144
pixels. You can resample it if you need to, but these measures are
mandatory since it is the resolution the traditional Game Boy uses.

step04
Convert your image to a paletted one by loading the palette we created a
few steps ago. I have used a Stucki dithering at 51% but you can use a
different one if you get a better result with it. You may be able to get
a preview of the result somewhere before actually converting it.

step05
We are going to separate each color plane to work better with them.
Duplicate your image three times so you get four copies of the same
picture.

step06
The first tricky step is erasing unnecessary planes from each image.
For each picture, if it is set as background, convert it to a layer, and
remove three of the four planes of gray, so you get a different plane in
each image. You may be able to do so with a "color transparency" tool.

step07
Resize the four images to 300% with no antialias.

step08
Now create a blank image, 480*432 (three times 160*144) and fill it
completely with a pattern of black pixels (image attached). We will use
it to fill each gray plane with this pixel effect.

step09
Tint every plane with pure black, we do this so the blending with the
previous image is done the right way. But remember which was the darkest
plane and which the brightest!

step10
Reconvert each plane to non-paletted color (i.e., 24 or 32 bits may be
enought). Copy the image from step08 in every plane and blend it with
the extracted pixels with an "Add" blend at 100%. Then, merge everything
with a white background. Now you should have four plain images which will
only differ in the drawn "pixels".

step11
Convert every image again to layer instead of a background and remove the
white background a similar way we did with the unnecessary planes from
step06.

step12
Create a green pixeled picture (image attached), 480*432, like in step08.

step13
Put (copy, paste) each plane on this new image with these properties:
- Darkest plane will have no blend.
- Next brighter plane will have a "Normal" blending at 67%.
- Next brighter plane will have it at 33%.
- You don't need to paste the brightest plane since it won't be visible.
Make sure you put the planes in the correct place!

step14
If you followed these steps correctly, you should have something like
the example image. It has four different gray tones with a pixelated
effect as it had been captured from a Game Boy screen. Nice!



A FASTER WORKAROUND, BUT GIVES WORSE RESULTS:

After you have done step04, you could resample the resulting image by
making it three times larger, then creating a new picture with the green
pixels layer and putting it above the step04 layer, and then changing the
blend options in the step04 picture until you get a proper result. It is
quite difficult to obtain good pictures from this procedure, since pixels
will look too dark or too bright, or there will be too much contrast. The
procedure described above gives the best results for me, with nice tones
and contrast, but it requires a bit more time. The result well worths it!



Hope you find this useful. For suggestions or comments, please refer to
stage7 at stg7 dot net.

Enjoy!

20071214