I’m pretty happy with how my header image (seen above) turned out. Here’s how it was made:
Step 1 - Find a font. I used Pixelzim 3x5
Step 2 - Generate a mask with Imagemagick:
| 1 | #!/bin/sh |
| 2 | |
| 3 | # If you're using a different font, you may want to fiddle with the |
| 4 | # pointsize, kerning and crop parameters. A monospaced font is highly |
| 5 | # recommended, but not required. |
| 6 | |
| 7 | echo "Building hex mask..." |
| 8 | convert -background black -extent 4094x2 label:" " hex.png |
| 9 | for i in `seq 1 410` |
| 10 | do |
| 11 | echo "Adding row $i..." |
| 12 | RANDHEX=`dd if=/dev/urandom bs=256 count=1 | xxd -p -u -c 256` |
| 13 | convert -background black -fill '#FFFFFF' \ |
| 14 | -font pzim3x5.ttf -pointsize 20 -kerning -2 \ |
| 15 | label:"$RANDHEX" -crop 4094x12+0+0 tmp.png |
| 16 | convert hex.png tmp.png -append hex2.png |
| 17 | mv hex2.png hex.png |
| 18 | done |
| 19 | echo "Executing final crop..." |
| 20 | convert hex.png -crop 4094x4090+0+2 hex_huge.png |
| 21 | rm hex.png |
Step 3 - Obtain a nice image to apply the mask to. I’ve used this one
Step 4 - Apply the mask:
| 1 | #!/bin/sh |
| 2 | # Supply image to apply mask to as first argument to script |
| 3 | IMG="$1"; |
| 4 | convert hex_huge.png -background black -gravity center -extent 4098x4094 hex.png |
| 5 | # Tweak the multiply and add values as needed |
| 6 | convert "$IMG" -evaluate multiply 0.40 -evaluate add 10% intr.png |
| 7 | convert hex.png intr.png -compose Darken -composite out.png |
| 8 | rm intr.png hex.png |
Step 5 - Crop the image. You can do it with an image editor such as GIMP or something like this in Imagemagick:
convert out.png -crop 708x306+1+0 cropped.png
I played around with the values a bit to find a good slice of the image to use.
Step 6 - Optimize file size.
$ convert cropped.png +dither -colors 64 quantized.png |
$ pngcrush -reduce -brute quantized.png crushed.png |
$ zopfli --png --i250 crushed.png -c > final.png |
You may want to experiment with different color depths depending on your source image.