/// <summary>
/// Crops image to given size
/// </summary>
/// <param name="startX"></param>
/// <param name="startY"></param>
/// <param name="endX"></param>
/// <param name="endY"></param>
public void Crop(int startX, int startY, int endX, int endY)
{
if (startX > endX || startY > endY || startX < 0 || startY < 0 ||
endX > data.GetLength(0) || endY > data.GetLength(1))
{
throw new ArgumentException("Invalid input");
}
Pixel[,] temp = new Pixel[endX - startX, endY - startY];
int xcount = startX;
int ycount = startY;
for (int i = 0; i < temp.GetLength(0); i++)
{
for (int j = 0; j < temp.GetLength(1); j++)
{
temp[i, j] = data[xcount, ycount];
ycount++;
}
ycount = startY;
xcount++;
}
data = temp;
}
/// <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));
}