// Encodes data to monochromatic-scale PNG file
func EncodeColor(file []byte, secDat [][]int) (png.Encoder, *image.RGBA) {
fSize := len(file)
min := 0
max := int(math.Sqrt(float64(fSize)))
binIndex := 0
fmt.Printf("[+] File size: %d\n", fSize)
fmt.Printf("[+] Max vector size: %d\n", max)
fmt.Printf("[+] Total vectors: %d\n", fSize/max)
binImage := image.NewRGBA(
image.Rect(min, min, max, max),
)
var c color.Color
sectionNumber := 0
// Fill the image with the file bytes
for y := min; y < max; y++ {
for x := min; x < max; x++ {
// Set section color delimiters
idxA := binIndex > secDat[sectionNumber][0]
idxB := binIndex < secDat[sectionNumber][1]
lim := sectionNumber < len(secDat)-1
// Increase section number
if binIndex > secDat[sectionNumber][1] && lim {
sectionNumber++
}
// If the same section map with color
if idxA && idxB && lim {
// Get a color for every different section
// NOTE: "sectionNumber%12" is for color table security, only 12 colors
// available at the moment.
c = GetColor(sectionNumber%12, file[binIndex])
} else {
c = color.RGBA{
uint8(file[binIndex]),
uint8(file[binIndex]),
uint8(file[binIndex]),
uint8(255),
}
}
binIndex++
binImage.Set(x, y, c)
}
}
var enc png.Encoder
enc.CompressionLevel = 0
return enc, binImage
}
// Encodes data to black and white PNG file
func EncodeBW(file []byte) (png.Encoder, *image.RGBA) {
fSize := len(file)
min := 0
max := int(math.Sqrt(float64(fSize)))
binIndex := 0
fmt.Printf("[+] File size: %d\n", fSize)
fmt.Printf("[+] Max vector size: %d\n", max)
fmt.Printf("[+] Total vectors: %d\n", fSize/max)
binImage := image.NewRGBA(
image.Rect(min, min, max, max),
)
var c color.Color
// Fill the image with the file bytes
for y := min; y < max; y++ {
for x := min; x < max; x++ {
c = color.RGBA{
uint8(file[binIndex]),
uint8(file[binIndex]),
uint8(file[binIndex]),
uint8(255),
}
binIndex++
binImage.Set(x, y, c)
}
}
var enc png.Encoder
enc.CompressionLevel = 0
return enc, binImage
}
