/// <summary>
/// given a location of a pixel (x,y), returns the info about that pixel.
/// </summary>
/// <param name="i"></param>
/// <param name="j"></param>
/// <param name="imageDataArray"></param>
/// <param name="injectedContext"></param>
/// <returns></returns>
public pixel getPixelInfo(int i, int j, byte[] imageDataArray, SeamCarvingContext injectedContext)
{
byte[] red = { 0, 0, 0, this.getPixel(imageDataArray, i, j, 0, injectedContext) };
byte[] green = { 0, 0, 0, this.getPixel(imageDataArray, i, j, 1, injectedContext) };
byte[] blue = { 0, 0, 0, this.getPixel(imageDataArray, i, j, 2, injectedContext) };
byte[] alpha = { 0, 0, 0, this.getPixel(imageDataArray, i, j, 3, injectedContext) };
if (BitConverter.IsLittleEndian)
{
Array.Reverse(red);
Array.Reverse(green);
Array.Reverse(blue);
Array.Reverse(alpha);
}
int redInt = BitConverter.ToInt32(red, 0);
int greenInt = BitConverter.ToInt32(green, 0);
int blueInt = BitConverter.ToInt32(blue, 0);
int alphaInt = BitConverter.ToInt32(alpha, 0);
pixel toReturn = new pixel();
toReturn.red = redInt;
toReturn.green = greenInt;
toReturn.blue = blueInt;
toReturn.alpha = alphaInt;
return toReturn;
}
/// <summary>
/// takes a given bitmapImage and copies it into a new byte array and returns it.
/// </summary>
/// <param name="img"></param>
/// <param name="injectedContext"></param>
/// <returns></returns>
public byte[] ImageToByte(BitmapImage toCopy, SeamCarvingContext injectedContext)
{
injectedContext.stride = toCopy.PixelWidth * 4;
int size = toCopy.PixelHeight * injectedContext.stride;
byte[] pixels = new byte[size];
toCopy.CopyPixels(pixels, injectedContext.stride, 0);
return pixels;
}
/// <summary>
/// find the minimum index in the right most column of a two dimensional array represented as a one dimensional array
/// </summary>
/// <param name="arr"></param>
/// <param name="injectedContext"></param>
/// <returns></returns>
public int findMinIndex(int[] arr, SeamCarvingContext injectedContext)
{
int lowest = Int32.MaxValue;
int toReturn = 0;
for (int i = 0; i < injectedContext.Height; i++)
{
int current = this.getIndex(arr, i, (int)injectedContext.Width - 2, injectedContext);
if (current < lowest)
{
lowest = current;
toReturn = i;
}
}
return toReturn;
}
/// <summary>
///
/// </summary>
/// <param name="injectedContext"></param>
public void calculateSeam(SeamCarvingContext injectedContext)
{
injectedContext.dirtyArray = new int[injectedContext.energy.Length];
int j = this.seamUtilities.findMinIndex(injectedContext.energy, injectedContext);
for (int i = (int)injectedContext.Width - 2; i >= 0; i--)
{
if (j == 0)
{
j += 1;
}
int up = this.seamUtilities.getIndex(injectedContext.energy, j + 1, i, injectedContext);
int lat = this.seamUtilities.getIndex(injectedContext.energy, j, i, injectedContext);
int down = this.seamUtilities.getIndex(injectedContext.energy, j - 1, i, injectedContext);
if (up < lat && up < down)
{
seamUtilities.setPixel(injectedContext.imageDataArray, j, i, 2, 0xff, injectedContext);
seamUtilities.setPixel(injectedContext.imageDataArray, j, i, 1, 0x00, injectedContext);
seamUtilities.setPixel(injectedContext.imageDataArray, j, i, 0, 0x00, injectedContext);
seamUtilities.setPixel(injectedContext.imageDataArray, j, i, 3, 0xff, injectedContext);
this.seamUtilities.setIndex(injectedContext.dirtyArray, j, i, 1, injectedContext);
j = j + 1;
}
else if (lat < down && lat < up)
{
seamUtilities.setPixel(injectedContext.imageDataArray, j, i, 2, 0xff, injectedContext);
seamUtilities.setPixel(injectedContext.imageDataArray, j, i, 1, 0x00, injectedContext);
seamUtilities.setPixel(injectedContext.imageDataArray, j, i, 3, 0xff, injectedContext);
seamUtilities.setPixel(injectedContext.imageDataArray, j, i, 0, 0x00, injectedContext);
this.seamUtilities.setIndex(injectedContext.dirtyArray, j, i, 1, injectedContext);
}
else
{
seamUtilities.setPixel(injectedContext.imageDataArray, j, i, 2, 0xff, injectedContext);
seamUtilities.setPixel(injectedContext.imageDataArray, j, i, 3, 0xff, injectedContext);
seamUtilities.setPixel(injectedContext.imageDataArray, j, i, 1, 0x00, injectedContext);
seamUtilities.setPixel(injectedContext.imageDataArray, j, i, 0, 0x00, injectedContext);
this.seamUtilities.setIndex(injectedContext.dirtyArray, j, i, 1, injectedContext);
j = j - 1;
}
}
}
/// <summary>
/// given a seam carving context, calculates the gradient of every pixel.
/// </summary>
/// <param name="injectedContext"></param>
public void calculateGradient(SeamCarvingContext injectedContext)
{
injectedContext.gradientArray = new byte[injectedContext.imageDataArray.Length];
for (int i = 1; i < injectedContext.Height - 1; i++)
{
for (int j = 1; j < injectedContext.Width - 1; j++)
{
pixel last = seamUtilities.getPixelInfo(i, j - 1, injectedContext.imageDataArray, injectedContext);
pixel current = seamUtilities.getPixelInfo(i, j, injectedContext.imageDataArray, injectedContext);
pixel next = seamUtilities.getPixelInfo(i, j + 1, injectedContext.imageDataArray, injectedContext);
byte gradient = calculateGradientOfPixel(last, current, next);
seamUtilities.setPixel(injectedContext.gradientArray, i, j, 0, gradient, injectedContext);
seamUtilities.setPixel(injectedContext.gradientArray, i, j, 1, gradient, injectedContext);
seamUtilities.setPixel(injectedContext.gradientArray, i, j, 2, gradient, injectedContext);
seamUtilities.setPixel(injectedContext.gradientArray, i, j, 3, 0xff, injectedContext);
}
}
}
/// <summary>
/// calculates the heatmap of the given seam carving context
/// </summary>
/// <param name="injectedContext"></param>
public void calculateHeat(SeamCarvingContext injectedContext)
{
injectedContext.energyArray = injectedContext.gradientArray;
injectedContext.energy = new int[injectedContext.gradientArray.Length / 4];
for (int i = 0; i < injectedContext.Height; i++)
{
byte current = this.seamUtilities.getPixel(injectedContext.gradientArray, i, 0, 0, injectedContext);
this.seamUtilities.setIndex(injectedContext.energy, i, 0, (int)current, injectedContext);
}
for (int i = 1; i < injectedContext.Width - 1; i++)
{
for (int j = 0; j < injectedContext.Height; j++)
{
if (j == 0 || j == (injectedContext.Height - 1))
{
this.seamUtilities.setIndex(injectedContext.energy, j, i, Int32.MaxValue, injectedContext);
}
else
{
int current = (int)this.seamUtilities.getPixel(injectedContext.gradientArray, j, i, 0, injectedContext);
int neg = this.seamUtilities.getIndex(injectedContext.energy, j - 1, i - 1, injectedContext);
int lat = this.seamUtilities.getIndex(injectedContext.energy, j, i - 1, injectedContext);
int pos = this.seamUtilities.getIndex(injectedContext.energy, j + 1, i - 1, injectedContext);
int least = (Math.Min(Math.Min(neg, lat), pos));
int toSet = current + least;
int maxVal = 255 * (int)injectedContext.Width;
this.seamUtilities.setIndex(injectedContext.energy, j, i, (current + least), injectedContext);
double ratio = (((double)toSet) / ((double)maxVal)) * 128;
byte pixelValue = (byte)(ratio * 256);
this.seamUtilities.setPixel(injectedContext.energyArray, j, i, 0, pixelValue, injectedContext);
this.seamUtilities.setPixel(injectedContext.energyArray, j, i, 1, pixelValue, injectedContext);
this.seamUtilities.setPixel(injectedContext.energyArray, j, i, 2, pixelValue, injectedContext);
}
}
}
}
/// <summary>
/// gets the pixel value from a given byte array at location (x,y) with the given color.
/// </summary>
/// <param name="arr"></param>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="color"></param>
/// <returns></returns>
public byte getPixel(byte[] arr, int x, int y, int color, SeamCarvingContext context)
{
int index = (int)context.Width * 4 * x + y * 4;
return arr[index + color];
}
/// <summary>
/// sets the pixel value in the given byte array at location (x,y) with the given color to the given value.
/// </summary>
/// <param name="arr"></param>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="color"></param>
/// <param name="toSet"></param>
public void setPixel(byte[] arr, int x, int y, int color, byte toSet, SeamCarvingContext context)
{
int index = (int)context.Width * 4 * x + y * 4;
arr[index + color] = toSet;
}
/// <summary>
/// get index form the given array.
/// </summary>
/// <param name="arr"></param>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="injectedContext"></param>
/// <returns></returns>
public int getIndex(int[] arr, int x, int y, SeamCarvingContext injectedContext)
{
int index = x * (int)injectedContext.Width + y;
return arr[index];
}
/// <summary>
/// set index of pixel in array
/// </summary>
/// <param name="arr"></param>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="toSet"></param>
/// <param name="injectedContext"></param>
public void setIndex(int[] arr, int x, int y, int toSet, SeamCarvingContext injectedContext)
{
int index = x * (int)injectedContext.Width + y;
arr[index] = toSet;
}
