-- DynamicBitsXXXImpl.meta
-- Copyright (C) 1984, 1985, Xerox Corporation. All rights reserved.
-- Michael Plass, November 6, 1985 9:52:38 am PST
-- PARAMETERS sKernelRadius, fKernelRadius, sModelRadius, fModelRadius, swathSize
DIRECTORY DynamicBits, Basics, ImagerPixelMap, ImagerSample, PixelMapOps;
DynamicBits102Impl: CEDAR PROGRAM
IMPORTS Basics, ImagerPixelMap, ImagerSample, PixelMapOps, DynamicBits
~ BEGIN OPEN DynamicBits;
KernelArray: TYPE ~ ARRAY [(-1)..2) OF ARRAY [(-1)..2) OF INTEGER;
SampleBuffer: TYPE ~ ImagerSample.SampleBuffer;
PixelRow: TYPE ~ RECORD[sOrigin, fOrigin: INTEGER, sample: SampleBuffer];
CreatePixelRow: PROC [s, f: INTEGER, size: NAT] RETURNS [PixelRow] ~ {
buffer: SampleBuffer ~ ImagerSample.NewBuffer[iSize: 1, jSize: size];
RETURN [[sOrigin: s, fOrigin: f, sample: buffer]]
};
CopyPixelRow: PROC [old: PixelRow] RETURNS [PixelRow] ~ {
new: PixelRow ~ CreatePixelRow[old.sOrigin, old.fOrigin, old.sample.jSize];
PixelMapOps.CopySamples[buffer: new.sample, bi: 0, bj: 0, count: old.sample.jSize, source: old.sample, si: 0, sj: 0];
RETURN [new]
};
ModelData: TYPE ~ REF ModelDataRep;
ModelDataRep: TYPE ~ ARRAY [0..2) OF REF ModelDataItem;
ModelDataItem: TYPE ~ RECORD [
intensity: Intensity,
noisePenalty: NoisePenalty,
a: KernelArray
];
ModelParameterFault: PUBLIC ERROR [data: REF] ~ CODE;
neighborhoodBounds: DeviceRectangle ~ [0, 0, 1, 1];
CheckNeighborhood: PROC [neighborhood: DeviceRectangle] ~ {
IF neighborhood # neighborhoodBounds THEN ModelParameterFault[$neighborhood];
};
kernelBounds: DeviceRectangle ~ [(-1), (-1), 3, 3];
CheckKernel: PROC [bounds: DeviceRectangle] ~ {
IF bounds # kernelBounds THEN ModelParameterFault[$kernel];
};
ArrayFromKernel: PROC [kernel: Kernel] RETURNS [kernelArray: KernelArray] ~ {
CheckKernel[kernel.Window];
FOR s: INTEGER IN [(-1)..2) DO
FOR f: INTEGER IN [(-1)..2) DO
kernelArray[s][f] ← LOOPHOLE[kernel.GetPixel[s, f], INTEGER];
ENDLOOP;
ENDLOOP;
};
CreatePrinterModel: PROC [neighborhood: DeviceRectangle, printerModel: PrinterModel, kernel: PixelMap] RETURNS [model: Model] ~ {
bitmap: PixelMap ← ImagerPixelMap.Create[0, neighborhood];
data: ModelData ← NEW[ModelDataRep];
kernelArray: KernelArray ← ArrayFromKernel[kernel];
CheckNeighborhood[neighborhood];
model ← NEW[ModelRep];
FOR encoding: CARDINAL IN [0..2) DO
intensity: Intensity;
noisePenalty: NoisePenalty;
scaledArray: KernelArray;
TRUSTED {
t: CARDINAL ← Basics.BITSHIFT[encoding, Basics.bitsPerWord-1];
bitmap ← MakePixelMapFromBits[@t, 1, neighborhoodBounds, bitmap.refRep];
};
[intensity, noisePenalty] ← printerModel[bitmap, encoding];
FOR s: INTEGER IN [(-1)..2) DO
FOR f: INTEGER IN [(-1)..2) DO
k: INTEGER ← kernelArray[s][f];
scaledArray[s][f] ←
IF k>=0 THEN (Basics.LongMult[k, intensity]+127)/255
ELSE -((Basics.LongMult[-k, intensity]+127)/255);
ENDLOOP;
ENDLOOP;
data[encoding] ← NEW[ModelDataItem ← [intensity, noisePenalty, scaledArray]];
ENDLOOP;
model.neighborhood ← neighborhood;
model.kernel ← kernel.Copy;
model.data ← data;
};
DoWithPrinterModel: PROC [model: Model, action: PROC[PrinterModel]] ~ {
data: ModelData ~ NARROW[model.data];
printerModel: PROC [bitmap: PixelMap, encoding: CARDINAL] RETURNS [Intensity, NoisePenalty] ~ {
item: REF ModelDataItem ~ data↑[encoding];
RETURN [item.intensity, item.noisePenalty];
};
action[printerModel];
};
StorePixelRow: PROC [p: PixelRow, pixelMap: PixelMap] ~ {
fMin: INTEGER ← MAX[p.fOrigin, pixelMap.fOrigin+pixelMap.fMin];
fMax: INTEGER ← MIN[p.fOrigin+p.sample.jSize, pixelMap.fOrigin+pixelMap.fMin+pixelMap.fSize];
IF fMax<=fMin THEN RETURN;
PixelMapOps.PutF[pixelMap: pixelMap, s: p.sOrigin, f: fMin, buffer: p.sample, bi: 0, bj: fMin-p.fOrigin, count: fMax-fMin];
};
Load: PROC [p: PixelRow, pixelMap: PixelMap] ~ {
-- Takes care of boundary conditions
fMin: INTEGER ← MAX[p.fOrigin, pixelMap.fOrigin+pixelMap.fMin];
fMax: INTEGER ← MIN[p.fOrigin+p.sample.jSize, pixelMap.fOrigin+pixelMap.fMin+pixelMap.fSize];
sMin: INTEGER ← MIN[MAX[p.sOrigin, pixelMap.sOrigin+pixelMap.sMin], pixelMap.sOrigin+pixelMap.sMin+pixelMap.sSize-1];
IF fMax<=fMin THEN {PixelMapOps.ClearSamples[buffer: p.sample, count: p.sample.jSize]; RETURN};
PixelMapOps.GetF[pixelMap: pixelMap, s: sMin, f: fMin, buffer: p.sample, bi: 0, bj: fMin-p.fOrigin, count: fMax-fMin];
FOR i: INTEGER IN [0..fMin-p.fOrigin) DO
p.sample[i] ← p.sample[fMin-p.fOrigin];
ENDLOOP;
FOR i: INTEGER IN [fMax-p.fOrigin..p.sample.jSize) DO
p.sample[i] ← p.sample[fMax-1-p.fOrigin];
ENDLOOP;
};
Convolve: PROC [pixelMap: PixelMap, kernel: Kernel, unitIntensity: CARDINAL] ~ {
bounds: DeviceRectangle ← pixelMap.BoundedWindow;
kernelArray: KernelArray ← ArrayFromKernel[kernel];
p: ARRAY [(-1)..2) OF PixelRow ← CreatePixelRows[];
CreatePixelRows: PROC RETURNS[p: ARRAY[(-1)..2) OF PixelRow]~{
FOR i: INTEGER IN [(-1)..2) DO
p[i] ← CreatePixelRow[bounds.sMin+i, bounds.fMin+(-1), bounds.fSize+3-1];
ENDLOOP;
};
q: PixelRow ← CopyPixelRow[p[0]];
kernelMag: INTEGER ← KernelWeight[kernel];
halfUnit: CARDINAL ← unitIntensity/2;
maxMag: INT ← Basics.LongMult[ABS[kernelMag], INT[unitIntensity]]+halfUnit;
Cd: PROC [i: INTEGER] RETURNS [CARDINAL] ~ INLINE {RETURN [LOOPHOLE[i]]};
short: BOOLEAN ← maxMag < CARDINAL.LAST;
FOR ss: INT IN [(-1)..2) DO
FOR ff: INT IN [(-1)..2) DO
short ← short AND kernelArray[ss][ff] >= 0;
ENDLOOP;
ENDLOOP;
FOR i: INTEGER IN [(-1)..2) DO Load[p[i], pixelMap] ENDLOOP;
THROUGH [0..bounds.sSize) DO
IF short THEN {
-- Use 16-bit arithemetic for greater speed.
FOR f: NAT IN [-(-1)..bounds.fSize-(-1)) DO
pix: CARDINAL ← p[-(-1)].sample[f-(-1)]*Cd[kernelArray[(-1)][(-1)]] + p[-(-1)].sample[f-0]*Cd[kernelArray[(-1)][0]] + p[-(-1)].sample[f-1]*Cd[kernelArray[(-1)][1]] + p[-0].sample[f-(-1)]*Cd[kernelArray[0][(-1)]] + p[-0].sample[f-0]*Cd[kernelArray[0][0]] + p[-0].sample[f-1]*Cd[kernelArray[0][1]] + p[-1].sample[f-(-1)]*Cd[kernelArray[1][(-1)]] + p[-1].sample[f-0]*Cd[kernelArray[1][0]] + p[-1].sample[f-1]*Cd[kernelArray[1][1]] + 0;
q.sample[f] ← (pix+halfUnit)/unitIntensity;
ENDLOOP;
}
ELSE {
FOR f: NAT IN [-(-1)..bounds.fSize-(-1)) DO
pix: INT ← 0;
FOR ss: INT IN [(-1)..2) DO
FOR ff: INT IN [(-1)..2) DO
pix ← pix + p[-ss].sample[f-ff]*INT[kernelArray[ss][ff]];
ENDLOOP;
ENDLOOP;
q.sample[f] ← (pix+halfUnit)/unitIntensity;
ENDLOOP;
};
StorePixelRow[q, pixelMap];
{t: PixelRow ← p[(-1)]; p[(-1)] ← p[0]; p[0] ← p[1]; p[2-1] ← t};
p[2-1].sOrigin ← p[2-1].sOrigin + (2-(-1));
Load[p[2-1], pixelMap];
q.sOrigin ← p[0].sOrigin;
ENDLOOP;
};
ApplyModel: PROC [bitmap: PixelMap, model: Model] RETURNS [PixelMap] ~ {
w: DeviceRectangle ← bitmap.Window;
gray: PixelMap ← ImagerPixelMap.Create[3, w];
bitRow: PixelRow ← CreatePixelRow[w.sMin+0, w.fMin+0, w.fSize+1];
indexRow: PixelRow ← CreatePixelRow[w.sMin, w.fMin, w.fSize];
destRow: PixelRow ← CopyPixelRow[indexRow];
data: ModelData ← NARROW[model.data];
MergeBits: PROC ~ {
FOR f: NAT IN [0..indexRow.sample.jSize) DO
k: CARDINAL ← 0;
FOR ff: NAT IN [f..f+1) DO
k ← k*2+bitRow.sample[ff];
ENDLOOP;
indexRow.sample[f] ← (indexRow.sample[f] * 2 + k) MOD 2;
ENDLOOP;
};
PixelMapOps.ClearSamples[buffer: bitRow.sample, count: bitRow.sample.jSize];
PixelMapOps.ClearSamples[buffer: indexRow.sample, count: indexRow.sample.jSize];
PixelMapOps.ClearSamples[buffer: destRow.sample, count: destRow.sample.jSize];
FOR i: NAT IN [0..1) DO
Load[bitRow, bitmap];
MergeBits[];
bitRow.sOrigin ← bitRow.sOrigin + 1;
ENDLOOP;
FOR s: NAT IN [0..w.sSize) DO
FOR f: NAT IN [0..destRow.sample.jSize) DO
destRow.sample[f] ← data[indexRow.sample[f]].intensity;
ENDLOOP;
StorePixelRow[destRow, gray];
destRow.sOrigin ← destRow.sOrigin + 1;
Load[bitRow, bitmap];
MergeBits[];
bitRow.sOrigin ← bitRow.sOrigin + 1;
ENDLOOP;
RETURN [gray]
};
TuneSwath: PROC [gray: PixelMap, bitmap: PixelMap, fixedBits: PixelMap, swath: DeviceRectangle, model: Model, scratch: REF] RETURNS [newScratch: REF] ~ {
-- Make sure the swath has the right fSize
xxx: [0..0] ← swath.fSize-2;
-- sOrigin and fOrigin give the position of the origin of the local swatch in the bitmap coordinate system.
sOrigin: INTEGER ← swath.sMin-1-1;
fOrigin: INTEGER ← swath.fMin;
pixelRow: PixelRow ← CreatePixelRow[sOrigin, fOrigin+(-2), 4-(-2)];
swathRow: PixelRow ← CreatePixelRow[sOrigin, fOrigin, 2];
bit: ARRAY [(-1)..2) OF ARRAY [(-2)..4) OF [0..1];
-- The current bits from the bitmap within the swatch
index: ARRAY [(-1)..2) OF ARRAY [(-2)..4) OF [0..2);
-- The current bits, packed up into indices into the model array
fixed: ARRAY [(-1)..2) OF ARRAY [0..2) OF [0..1];
-- A local copy of a piece of fixedBits
target: ARRAY [(-1)..3) OF INTEGER;
-- A local copy of a piece of gray
trial: ARRAY [(-1)..3) OF INTEGER;
-- The partially computed approximation to the gray
modelData: ModelData ← NARROW[model.data];
nonFixedBitCount: NAT ← 0;
SF: TYPE ~ RECORD [s: [(-1)..2), f: [0..2)];
nonFixedBitIndex: ARRAY [0..(2-(-1))*2) OF SF;
questionBits: [0..4);
-- The bits that need to be determined for a given context.
contextBits: [0..16);
-- The context bits in the swath.
prevContextBits: [0..16);
-- The context bits for the previous subproblem.
SubproblemSolution: TYPE ~ RECORD [
setting: [0..4),
-- The setting of questionBits that achieves the lowest total penalty for the swath so far.
minErrHighHalf: [0..CARDINAL.LAST/4],
minErrLowHalf: CARDINAL
-- The lowest total penalty for the swath so far.
-- Packed so the whole thing fits in two words, since there are a lot of them.
];
MakeSubproblemSolution: PROC [setting: [0..4), minErr: INT] RETURNS [SubproblemSolution] ~ INLINE BEGIN
long: Basics.LongNumber ← [li[minErr]];
RETURN [[setting: setting, minErrHighHalf: long.highbits, minErrLowHalf: long.lowbits]]
END;
MinErr: PROC [s: SubproblemSolution] RETURNS [INT] ~ INLINE BEGIN
long: Basics.LongNumber ← [num[lowbits: s.minErrLowHalf, highbits: s.minErrHighHalf]];
RETURN [long.li]
END;
PerSwatchTable: TYPE ~ ARRAY [0..16) OF SubproblemSolution;
avail: LIST OF REF PerSwatchTable ← NARROW[scratch];
subproblemTable: LIST OF REF PerSwatchTable ← NIL;
Alloc: PROC RETURNS [new: LIST OF REF PerSwatchTable] ~ BEGIN
IF avail = NIL THEN new ← LIST[NEW[PerSwatchTable]]
ELSE {
new ← avail;
avail ← avail.rest;
new.rest ← NIL;
};
new.first↑ ← ALL[[0, CARDINAL.LAST/4, CARDINAL.LAST]];
END;
ComputeFixedIndex: PROC ~ BEGIN
nonFixedBitCount ← 0;
FOR s: [(-1)..2) IN [(-1)..2) DO
FOR f: [0..2) IN [0..2) DO
IF fixed[s][f] = 0 THEN {
nonFixedBitIndex[nonFixedBitCount] ← [s,f];
nonFixedBitCount ← nonFixedBitCount + 1;
};
ENDLOOP;
ENDLOOP;
END;
Initialize: PROC ~ BEGIN
FOR s: [(-1)..2) IN [(-1)..2) DO
pixelRow.sOrigin ← sOrigin+s;
Load[pixelRow, bitmap];
FOR f: [(-2)..4) IN [(-2)..4) DO
bit[s][f] ← pixelRow.sample[f+fOrigin-pixelRow.fOrigin];
ENDLOOP;
IF s+sOrigin NOT IN [swath.sMin..swath.sMin+swath.sSize)
THEN fixed[s] ← ALL[1]
ELSE {
swathRow.sOrigin ← sOrigin+s;
Load[swathRow, fixedBits];
FOR f: [0..2) IN [0..2) DO
fixed[s][f] ← swathRow.sample[f+fOrigin-swathRow.fOrigin];
ENDLOOP;
};
ENDLOOP;
pixelRow.sOrigin ← sOrigin;
Load[pixelRow, gray];
FOR f: INTEGER IN [(-1)..3) DO
target[f] ← pixelRow.sample[f+fOrigin-pixelRow.fOrigin];
ENDLOOP;
ComputeOuterModelIndices[];
ComputePartialTrial[];
ComputeFixedIndex[];
END;
Advance: PROC ~ BEGIN
sOrigin ← sOrigin + 1;
FOR s: [(-1)..2) IN [(-1)..2-1) DO
bit[s] ← bit[s+1];
fixed[s] ← fixed[s+1];
ENDLOOP;
pixelRow.sOrigin ← sOrigin+2-1;
Load[pixelRow, bitmap];
FOR f: [(-2)..4) IN [(-2)..4) DO
bit[2-1][f] ← pixelRow.sample[f+fOrigin-pixelRow.fOrigin];
ENDLOOP;
IF 2-1+sOrigin NOT IN [swath.sMin..swath.sMin+swath.sSize)
THEN fixed[2-1] ← ALL[1]
ELSE {
swathRow.sOrigin ← sOrigin+2-1;
Load[swathRow, fixedBits];
FOR f: [0..2) IN [0..2) DO
fixed[2-1][f] ← swathRow.sample[f+fOrigin-swathRow.fOrigin];
ENDLOOP;
};
pixelRow.sOrigin ← sOrigin;
Load[pixelRow, gray];
FOR f: INTEGER IN [(-1)..3) DO
target[f] ← pixelRow.sample[f+fOrigin-pixelRow.fOrigin];
ENDLOOP;
ComputeOuterModelIndices[];
ComputePartialTrial[];
ComputeFixedIndex[];
END;
ComputeOuterModelIndices: PROC ~ BEGIN
index[(-1)][(-2)] ← bit[(-1)][(-2)];
index[(-1)][(-1)] ← bit[(-1)][(-1)];
index[(-1)][2] ← bit[(-1)][2];
index[(-1)][3] ← bit[(-1)][3];
index[0][(-2)] ← bit[0][(-2)];
index[0][(-1)] ← bit[0][(-1)];
index[0][2] ← bit[0][2];
index[0][3] ← bit[0][3];
index[1][(-2)] ← bit[1][(-2)];
index[1][(-1)] ← bit[1][(-1)];
index[1][2] ← bit[1][2];
index[1][3] ← bit[1][3];
END;
ComputeInnerModelIndices: PROC ~ BEGIN
index[(-1)][0] ← bit[(-1)][0];
index[(-1)][1] ← bit[(-1)][1];
index[0][0] ← bit[0][0];
index[0][1] ← bit[0][1];
index[1][0] ← bit[1][0];
index[1][1] ← bit[1][1];
END;
ComputePartialTrial: PROC ~ BEGIN
-- From the index values
t: REF ModelDataItem ← NIL;
trial ← ALL[0];
t ← modelData[index[(-1)][(-2)]];
trial[(-1)] ← trial[(-1)] + t.a[1][1];
t ← modelData[index[(-1)][(-1)]];
trial[(-1)] ← trial[(-1)] + t.a[1][0];
trial[0] ← trial[0] + t.a[1][1];
t ← modelData[index[(-1)][2]];
trial[1] ← trial[1] + t.a[1][(-1)];
trial[2] ← trial[2] + t.a[1][0];
t ← modelData[index[(-1)][3]];
trial[2] ← trial[2] + t.a[1][(-1)];
t ← modelData[index[0][(-2)]];
trial[(-1)] ← trial[(-1)] + t.a[0][1];
t ← modelData[index[0][(-1)]];
trial[(-1)] ← trial[(-1)] + t.a[0][0];
trial[0] ← trial[0] + t.a[0][1];
t ← modelData[index[0][2]];
trial[1] ← trial[1] + t.a[0][(-1)];
trial[2] ← trial[2] + t.a[0][0];
t ← modelData[index[0][3]];
trial[2] ← trial[2] + t.a[0][(-1)];
t ← modelData[index[1][(-2)]];
trial[(-1)] ← trial[(-1)] + t.a[(-1)][1];
t ← modelData[index[1][(-1)]];
trial[(-1)] ← trial[(-1)] + t.a[(-1)][0];
trial[0] ← trial[0] + t.a[(-1)][1];
t ← modelData[index[1][2]];
trial[1] ← trial[1] + t.a[(-1)][(-1)];
trial[2] ← trial[2] + t.a[(-1)][0];
t ← modelData[index[1][3]];
trial[2] ← trial[2] + t.a[(-1)][(-1)];
END;
ComputeRowPenalty: PROC RETURNS [penalty: CARDINAL] ~ BEGIN
-- From the index values
t: REF ModelDataItem ← NIL;
try: ARRAY [(-1)..3) OF INTEGER ← trial;
t ← modelData[index[(-1)][0]];
try[(-1)] ← try[(-1)] + t.a[1][(-1)];
try[0] ← try[0] + t.a[1][0];
try[1] ← try[1] + t.a[1][1];
t ← modelData[index[(-1)][1]];
try[0] ← try[0] + t.a[1][(-1)];
try[1] ← try[1] + t.a[1][0];
try[2] ← try[2] + t.a[1][1];
t ← modelData[index[0][0]];
try[(-1)] ← try[(-1)] + t.a[0][(-1)];
try[0] ← try[0] + t.a[0][0];
try[1] ← try[1] + t.a[0][1];
t ← modelData[index[0][1]];
try[0] ← try[0] + t.a[0][(-1)];
try[1] ← try[1] + t.a[0][0];
try[2] ← try[2] + t.a[0][1];
t ← modelData[index[1][0]];
try[(-1)] ← try[(-1)] + t.a[(-1)][(-1)];
try[0] ← try[0] + t.a[(-1)][0];
try[1] ← try[1] + t.a[(-1)][1];
t ← modelData[index[1][1]];
try[0] ← try[0] + t.a[(-1)][(-1)];
try[1] ← try[1] + t.a[(-1)][0];
try[2] ← try[2] + t.a[(-1)][1];
penalty ← 0 + ABS[try[(-1)]-target[(-1)]] + modelData[index[0][(-1)]].noisePenalty + ABS[try[0]-target[0]] + modelData[index[0][0]].noisePenalty + ABS[try[1]-target[1]] + modelData[index[0][1]].noisePenalty + ABS[try[2]-target[2]] + modelData[index[0][2]].noisePenalty;
END;
SetCombination: PROC [k: CARDINAL] ~ BEGIN
-- k is a packed version of the non-fixed bits
-- Sets questionBits and contextBits
FOR i: NAT IN [0..nonFixedBitCount) DO
sf: SF ← nonFixedBitIndex[i];
bit[sf.s][sf.f] ← k MOD 2;
k ← k/2;
ENDLOOP;
questionBits ← (bit[(-1)][0]*2 + bit[(-1)][1]);
contextBits ← (((bit[0][0]*2 + bit[0][1])*2 + bit[1][0])*2 + bit[1][1]);
IF k # 0 THEN ERROR;
prevContextBits ← contextBits/4 +
questionBits*(16/4);
END;
UnpackBits: PROC [questionBits, contextBits: CARDINAL] ~ BEGIN
-- Unpacks the args into the swath portion of the bit array
k: CARDINAL ← contextBits+questionBits*16;
bit[1][1] ← k MOD 2;
k ← k / 2;
bit[1][0] ← k MOD 2;
k ← k / 2;
bit[0][1] ← k MOD 2;
k ← k / 2;
bit[0][0] ← k MOD 2;
k ← k / 2;
bit[(-1)][1] ← k MOD 2;
k ← k / 2;
bit[(-1)][0] ← k MOD 2;
k ← k / 2;
END;
DoDynamicProgramming: PROC ~ {
-- If subproblemTable#NIL, subproblemTable.first gives the best ways to color the pixels up to sOrigin
UNTIL sOrigin = swath.sMin+swath.sSize DO
Initialize[];
BEGIN
nComb: NAT ← Basics.BITSHIFT[1, nonFixedBitCount];
new: LIST OF REF PerSwatchTable ← Alloc[];
pst: REF PerSwatchTable ← new.first;
prevPST: REF PerSwatchTable ← NIL;
IF subproblemTable # NIL THEN prevPST ← subproblemTable.first;
FOR k: NAT IN [0..nComb) DO
totBad: INT ← 0;
SetCombination[k];
ComputeInnerModelIndices[];
IF prevPST # NIL THEN totBad ← MinErr[prevPST[prevContextBits]];
totBad ← totBad+ComputeRowPenalty[];
IF totBad < MinErr[pst[contextBits]] THEN {
pst[contextBits] ← MakeSubproblemSolution[questionBits, totBad];
};
ENDLOOP;
new.rest ← subproblemTable;
subproblemTable ← new;
END;
sOrigin ← sOrigin + 1;
ENDLOOP;
};
Traceback: PROC ~ {
lowestPenalty: INT ← MinErr[subproblemTable.first[0]];
contextBits ← 0;
-- First look through the most recent subproblem to find the best entry.
FOR i: NAT IN (0..16) DO
err: INT ← MinErr[subproblemTable.first[i]];
IF err < lowestPenalty THEN {
lowestPenalty ← err;
contextBits ← i;
};
ENDLOOP;
sOrigin ← swath.sMin+swath.sSize;
FOR t: LIST OF REF PerSwatchTable ← subproblemTable, t.rest WHILE sOrigin-1 > swath.sMin DO
questionBits ← t.first[contextBits].setting;
sOrigin ← sOrigin - 1;
UnpackBits[questionBits, contextBits];
swathRow.sOrigin ← sOrigin;
FOR j: NAT IN [0..swathRow.sample.jSize) DO
swathRow.sample[j] ← bit[0][j];
ENDLOOP;
StorePixelRow[swathRow, bitmap];
contextBits ← contextBits/4 +
questionBits*(16/4);
ENDLOOP;
};
DoDynamicProgramming[];
Traceback[];
newScratch ← subproblemTable;
};
DynamicBits.RegisterImpl[[
sKernelRadius: 1,
fKernelRadius: 1,
sModelRadius: 0,
fModelRadius: 0,
swathSize: 2,
CreatePrinterModel: CreatePrinterModel,
DoWithPrinterModel: DoWithPrinterModel,
Convolve: Convolve,
ApplyModel: ApplyModel,
TuneSwath: TuneSwath
]];
END.