/// <summary>
/// Converts a string (usually from file) to an Image object
/// </summary>
/// <param name="imgData">the image data in string format</param>
/// <returns>the deserialized Image</returns>
public Image Parse(string imgData)
{
string formatRgx = '^' + formatSpec + '$';
string commentRgx = '^' + commentTag + ".+$";
string sizeRgx = @"^\d+ \d+$";
string rangeRgx = @"^\d+$";
string pixelRgx = @"^(:?\d+ ?)+$";
//each line in the "file"
string[] lines = imgData.Split
(new string[] { Environment.NewLine },
StringSplitOptions.None);
//the minimum length of any pgm file is 4 lines
if (lines.Length < 4)
{
throw new InvalidDataException
("Invalid number of lines " + lines.Length +
" is not enough");
}
//first line should be format specifier
checkFormat(lines[0], true, 0, formatRgx);
//second line should be either comment or size specifier
checkOneFormat(lines[1], true, 1, commentRgx, sizeRgx);
string[] metadata = lines.Skip(1) //skip format specifier
.TakeWhile(line => checkFormat(line, false, -1, commentRgx))
//take only metadata lines, line numbering is irrelevant here
.Select(comment => comment = comment.Substring(1)) //remove #
.ToArray();
//line after comments should be size specifier
checkFormat(lines[metadata.Length + 1], true,
metadata.Length + 1, sizeRgx);
int[] size = lines[metadata.Length + 1].Split(' ')
.Select(num => int.Parse(num))
.ToArray();
//line after size specifier should be range
checkFormat(lines[metadata.Length + 2], true,
metadata.Length + 2, rangeRgx);
int maxRange = int.Parse(lines[metadata.Length + 2]);
//the rest of the string should be filled with pixels
for (int i = metadata.Length + 3; i < lines.Length; i++)
{
checkFormat(lines[i], true, i, pixelRgx);
}
int[] pixelsData = lines.Skip(metadata.Length + 3) //skip metadata and stuff
.Select(line => line.Split(' ').Select(num => int.Parse(num)))
//parse each collection of collection
.SelectMany(list => list.ToArray()).ToArray();
//flatten the array
//verify maxRange of each pixel
for (int i = 0; i < pixelsData.Length; i++)
{
if (pixelsData[i] > maxRange)
{
throw new InvalidDataException
("Pixel " + i + " expected at most : " +
maxRange + Environment.NewLine + "Actual : " +
pixelsData[i]);
}
}
//checking amount of pixel corresponds to specified size
if (pixelsData.Length != size[0] * size[1])
{
throw new InvalidDataException("Expected size : " +
size[0] * size[1] + ", Actual size : "
+ pixelsData.Length);
}
//filling the resulting Pixel rectangular array
Pixel[,] pixels = new Pixel[size[0], size[1]];
for (int i = 0; i < pixelsData.Length; i++)
{
pixels[i % pixels.GetLength(0),
i / pixels.GetLength(0)] =
new Pixel(pixelsData[i]);
}
return(new Image(string.Join(Environment.NewLine, metadata),
maxRange, pixels));
}
public Image Parse(string imageData)
{
// Getting information from string
string[] lines = imageData.Split(new string[] { System.Environment.NewLine }, StringSplitOptions.None);
int currentLine = 1;
string metadata = "";
while (currentLine < lines.Length)
{
if (lines[currentLine].StartsWith("#"))
{
metadata += lines[currentLine].Substring(2) + System.Environment.NewLine;
}
else
{
break;
}
currentLine++;
}
metadata = metadata.Trim();
string[] widthHeight = lines[currentLine].Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
string widthInString = widthHeight[0].Trim();
string heightInString = widthHeight[1].Trim();
currentLine++;
string maxRangeInString = lines[currentLine].Trim();
currentLine++;
List <string> numbersInStrings = new List <string>();
while (currentLine < lines.Length)
{
string[] numbersOnLine = lines[currentLine].Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
foreach (string number in numbersOnLine)
{
numbersInStrings.Add(number);
}
currentLine++;
}
// Validating the information and parsing it into the right type
int width;
int height;
if (int.TryParse(widthInString, out width) == false)
{
throw new InvalidDataException();
}
if (int.TryParse(heightInString, out height) == false)
{
throw new InvalidDataException();
}
if (width <= 0 || height <= 0)
{
throw new InvalidDataException();
}
int maxRange;
if (int.TryParse(maxRangeInString, out maxRange) == false)
{
throw new InvalidDataException();
}
if (maxRange <= 0)
{
throw new InvalidDataException();
}
if (numbersInStrings.Count / 3.0 != height * width)
{
throw new InvalidDataException();
}
int[] numbers = new int[numbersInStrings.Count];
for (int i = 0; i < numbersInStrings.Count; i++)
{
int number;
if (int.TryParse(numbersInStrings[i], out number) == false)
{
throw new InvalidDataException();
}
if (number > maxRange)
{
throw new InvalidDataException();
}
numbers[i] = number;
}
// Creating image object
int red = 0;
int green = 0;
int blue = 0;
List <Pixel> pixels = new List <Pixel>();
for (int i = 0; i < numbers.Length; i++)
{
if (i % 3 == 0)
{
red = numbers[i];
}
else if ((i - 1) % 3 == 0)
{
green = numbers[i];
}
else if ((i - 2) % 3 == 0)
{
blue = numbers[i];
Pixel pixel = new Pixel(red, green, blue);
pixels.Add(pixel);
}
}
// Putting all the values from pixels list (1D) into the image 2D array
Pixel[,] image = new Pixel[height, width];
for (int row = 0; row < height; row++)
{
for (int column = 0; column < width; column++)
{
image[row, column] = pixels[row * width + column];
}
}
return(new Image(metadata, maxRange, image));
}
