Choose your colors:
- Open original file in Photoshop
- Select relevant areas (“Marquee”)
- Choose: Selection > Save Selection…
- Enter name eg: “Colors” and hit “Save”
Remove transparent areas:
- Select layer alpha (“CMD+Click” on layer)
- Switch to Quick Mask mode (Hit “Q”)
- Choose: Image > Adjustments > Threshold
- Set “Level” to 255 and “Save”
- Leave Quick mask mode (Hit “Q”)
- Choose: Select > Inverse
- Remove transparent parts (Hit “Backspace”)
Export indexed image:
- Choose: Save > Save for Web & Devices…
- Select: PNG 8, Selective, 200 Colors, No Dither
- Click “Modify Color Reduction…”
- Choose Channel: “Colors” and hit “Ok”
- Set Matte to Pink
- Leave “Interlace” unchecked
- Check “Transparency”
- Hit “Save” and name it “sprite_index.png”
Select transparency areas only:
- Open original file in Fireworks
- Rename layer to “alpha”
- Choose: File > Import… “sprite_index.png”
- Rename layer to “index”
- Select transparency (“ALT+Click” on indexed layer)
- Select original layer and remove colors (Hit “Backspace”)
- Hide “index” layer
Export alpha channel only:
- Switch to “Preview” mode
- Select: PNG8, Adaptive, 30 Colors, Dither 0, Alpha Transparency
- Choose File > Export… and name it “sprite_alpha.png”
Merge indexed and alpha channel:
- Open “sprite_alpha.png” in Fireworks
- Choose: File > Import… “sprite_index.png”
- Choose: File > Save As… and name it “sprite_merged.png”
Quantize merged image:
- Download pngquant from http://pornel.net/pngquant
- Put it into your image path
- Open terminal and run “pngquant sprite_merged.png”
- Bingo: The result “sprite_merged-fs8.png” is your 8 bit baby!