private void HandleFirstRow(IImagePredictor imagePredictor)
{
const byte a = 0;
const byte c = 0;
for (int column = 1; column < imageSize; column++)
{
var b = ImageCodes[0, column - 1];
var predictedValue = imagePredictor.PredictValue(a, b, c);
ImageCodes[0, column] = (byte)(predictedValue + ErrorMatrix[0, column]);
}
}
private void HandleFirstColumn(IImagePredictor imagePredictor)
{
const byte b = 0;
const byte c = 0;
for (int row = 1; row < imageSize; row++)
{
var a = ImageCodes[row - 1, 0];
var predictedValue = imagePredictor.PredictValue(a, b, c);
ImageCodes[row, 0] = (byte)(predictedValue + ErrorMatrix[row, 0]);
}
}
private void HandleFirstRow(IImagePredictor imagePredictor)
{
const byte a = 0;
const byte c = 0;
for (int column = 1; column < OriginalImage.Height; column++)
{
var b = ImageCodes[0, column - 1];
var prediction = imagePredictor.PredictValue(a, b, c);
HandlePrediction(0, column, prediction);
}
}
private void HandleFirstColumn(IImagePredictor imagePredictor)
{
const byte b = 0;
const byte c = 0;
for (int row = 1; row < OriginalImage.Width; row++)
{
var a = ImageCodes[row - 1, 0];
var prediction = imagePredictor.PredictValue(a, b, c);
HandlePrediction(row, 0, prediction);
}
}
public void EncodeImage(IFileReader fileReader, IFileWriter fileWriter, IImagePredictor imagePredictor)
{
if (fileReader == null)
{
throw new ArgumentNullException(nameof(fileReader));
}
if (fileWriter == null)
{
throw new ArgumentNullException(nameof(fileWriter));
}
if (imagePredictor == null)
{
throw new ArgumentNullException(nameof(imagePredictor));
}
ValidateImageFromFileReader(fileReader);
GetImageFromFileReader(fileReader);
ImageCodes = new byte[OriginalImage.Width, OriginalImage.Height];
PredictionMatrix = new byte[OriginalImage.Width, OriginalImage.Height];
ErrorMatrix = new int[OriginalImage.Width, OriginalImage.Height];
UpdateImageCodes();
HandleFirstPixel();
HandleFirstColumn(imagePredictor);
HandleFirstRow(imagePredictor);
for (int row = 1; row < 256; row++)
{
for (int column = 1; column < 256; column++)
{
var a = ImageCodes[row - 1, column];
var b = ImageCodes[row, column - 1];
var c = ImageCodes[row - 1, column - 1];
var prediction = imagePredictor.PredictValue(a, b, c);
HandlePrediction(row, column, prediction);
}
}
CopyBitmapHeader(fileReader, fileWriter);
WriteUsedImagePredictor(fileWriter, imagePredictor);
errorMatrixWriter.WriteErrorMatrix(ErrorMatrix, fileWriter);
fileWriter.Flush();
}