public override void Encode(IntField image, Stream output)
{
/// Split background from foreground. Anything with low "rectangularity" goes into foreground
/// - measure the number of "turns" (changes from horz to vert edge) against area.
/// Background:
/// - Predictive xform with small radius
/// - Modified runlengths
/// - Context-aware arithmetic encoding
/// Foreground:
/// - Order colors by how common they are, call them c1,c2,c3
/// - Flatten all colors into 0 and 1
/// - Find all rects covering all c2-pixels without covering any c1-pixels.
/// - Find all rects covering all c3-pixels without covering any c1 or c2 pixels.
/// - Predictive xform on 0/1 image stopping at vertical letter boundaries. If larger image not in dict, use a smaller one and add all sizes to dict.
/// - Modified runlengths on the 0/1 xformed
/// - Context-aware arithmetic encoding
/// - Rects: optimize by changing 1 pixel rects to pixels; then feed optim ints through arithmetic
/// Modified runlengths:
/// - As before, encode only runs of 0's.
/// - Every run longer than thresh encoded as thresh + a number in a separate optim stream
/// - Optim stream is fed through arithmetic
///
/// Alternative color encoding: a stream of 1's, 2's, 3's, fed through runlength
image.ArgbTo4c();
AddImageGrayscale(image, 0, 3, "00-original");
IntField backgr, foregr;
backgroundSplit(image, out backgr, out foregr);
// Backgr
backgr.PredictionEnTransformXor(new FixedSizeForeseer(5, 3, 2, new HorzVertForeseer()));
AddImageGrayscale(backgr, 0, 3, "20-bkg-xformed");
saveColors(foregr);
// save as much as possible using rects, the rest just dumping as-is
// Foregr
IntField foremap = foregr.Clone();
foremap.Map(pix => pix == 0 ? 0 : 1);
AddImageGrayscale(foremap, 0, 1, "30-fore-map");
foremap.PredictionEnTransformXor(new FixedSizeForeseer(7, 7, 3, new HorzVertForeseer()));
AddImageGrayscale(foremap, 0, 1, "31-fore-map-xformed");
saveForeground(foremap.Data);
}
public static int[] FieldcodeRunlengthsEn2(IntField image, SymbolCodec runlengthCodec, Compressor compr)
{
compr.AddImageGrayscale(image, 0, 3, "xformed");
List <int> data = new List <int>();
for (int i = 1; i <= 3; i++)
{
IntField temp = image.Clone();
temp.Map(x => x == i ? 1 : 0);
data.AddRange(temp.Data);
compr.AddImageGrayscale(temp, 0, 1, "field" + i);
}
var runs = runlengthCodec.Encode(data.ToArray());
compr.SetCounter("runs", runs.Length);
return(runs);
}
public static List <int[]> FieldcodeRunlengthsEn(IntField image, SymbolCodec runlengthCodec, Compressor compr)
{
compr.AddImageGrayscale(image, 0, 3, "xformed");
var fields = new List <int[]>();
for (int i = 1; i <= 3; i++)
{
IntField temp = image.Clone();
temp.Map(x => x == i ? 1 : 0);
var field = runlengthCodec.Encode(temp.Data);
CodecUtil.Shift(field, 1);
compr.SetCounter("symbols|field-" + i, field.Length);
fields.Add(field);
compr.AddImageGrayscale(temp, 0, 1, "field" + i);
}
return(fields);
}
public override void Encode(IntField image, Stream output)
{
// Predictive transform
image.ArgbTo4c();
image.PredictionEnTransformXor(Seer);
// Convert to three fields' runlengths
for (int i = 1; i <= 3; i++)
{
IntField temp = image.Clone();
temp.Map(x => x == i ? 1 : 0);
AddImageGrayscale(temp, 0, 1, "field" + i);
var runs = new RunLength01SplitCodec().EncodeSplit(temp.Data);
SetCounter("runs|field{0}|0s".Fmt(i), runs.Item1.Count);
SetCounter("runs|field{0}|1s".Fmt(i), runs.Item2.Count);
AddIntDump("field{0}-0s".Fmt(i), runs.Item1);
AddIntDump("field{0}-1s".Fmt(i), runs.Item2);
}
}
private void saveColors(IntField foregr)
{
var clr = foregr.Data.Where(pix => pix > 0).ToArray();
Tuple <int, int>[] cc = new Tuple <int, int> [3];
cc[0] = new Tuple <int, int>(clr.Where(pix => pix == 1).Count(), 1);
cc[1] = new Tuple <int, int>(clr.Where(pix => pix == 2).Count(), 2);
cc[2] = new Tuple <int, int>(clr.Where(pix => pix == 3).Count(), 3);
cc = cc.OrderBy(tup => - tup.Item1).ToArray();
int c1 = cc[0].Item2;
int c2 = cc[1].Item2;
int c3 = cc[2].Item2;
IntField cover = foregr.Clone();
cover.Map(pix => pix == c1 ? 1 : pix == c2 ? 5 : 0);
AddImageGrayscale(cover, 0, 5, "25-cover-2s");
cover = foregr.Clone();
cover.Map(pix => pix == c1 ? 1 : pix == c2 ? 1 : pix == c3 ? 5 : 0);
AddImageGrayscale(cover, 0, 5, "26-cover-3s");
AddIntDump("colors", clr);
List <int>[] runs = new List <int> [4];
runs[1] = new List <int>();
runs[2] = new List <int>();
runs[3] = new List <int>();
int p = 0;
while (p < clr.Length)
{
for (int c = 1; c <= 3; c++)
{
int pbefore = p;
while (p < clr.Length && clr[p] == c)
{
p++;
}
runs[c].Add(p - pbefore);
}
}
runs[1].Add(0);
runs[2].Add(0);
runs[3].Add(0);
AddIntDump("color-runs-1", runs[1]);
AddIntDump("color-runs-2", runs[2]);
AddIntDump("color-runs-3", runs[3]);
List <int>[] leftovers = new List <int> [4];
leftovers[1] = mrleCutOff(runs[1], 31);
leftovers[2] = mrleCutOff(runs[2], 31);
leftovers[3] = mrleCutOff(runs[3], 31);
ulong[][] probs1 = mrleGetProbs(runs[1].ToArray(), 31);
ulong[][] probs2 = mrleGetProbs(runs[2].ToArray(), 31);
ulong[][] probs3 = mrleGetProbs(runs[3].ToArray(), 31);
SetCounter("bytes|colors|probs", -1);
SetCounter("bytes|colors|shortruns|1", mrleEncodeShort(runs[1].ToArray(), probs1).Length);
SetCounter("bytes|colors|shortruns|2", mrleEncodeShort(runs[2].ToArray(), probs2).Length);
SetCounter("bytes|colors|shortruns|3", mrleEncodeShort(runs[3].ToArray(), probs3).Length);
SetCounter("bytes|colors|longruns|1", mrleEncodeLong(leftovers[1].ToArray()).Length);
SetCounter("bytes|colors|longruns|2", mrleEncodeLong(leftovers[2].ToArray()).Length);
SetCounter("bytes|colors|longruns|3", mrleEncodeLong(leftovers[3].ToArray()).Length);
}