//saves the image as a .png image
private async void SavePNG(object sender, RoutedEventArgs e)
{
LDRImage HDRPreview = new LDRImage();
await HDRPreview.LoadFromBytes(HDRI.Transform(), HDRI.Width, HDRI.Height);
HDRPreview.SaveFile();
}
//Called when the play button is pressed
private async void Recalculate(object sender, TappedRoutedEventArgs e)
{
//Re-renders the HDR image based on the new slider value
HDRI = Blending.Blend(sliderValue / 100f, underExp, regExp, overExp);
//Creates and displays a preview LDR image based off of the HDR image
HDRPreview = new LDRImage();
await HDRPreview.LoadFromBytes(HDRI.Transform(), HDRI.Width, HDRI.Height);
HDRImage.Source = HDRPreview.GetBitmapImage();
RecalculateButton.IsEnabled = false;
}
/// <summary>
/// Shows a specified channel in the loaded <see cref="HDRI"/>
/// </summary>
/// <param name="channel">I think 0 is red?</param>
private async void ShowChannel(int channel)
{
SaveButton.IsEnabled = false;
RecalculateButton.IsEnabled = false;
BlenderSlider.IsEnabled = false;
if (HDRI == null)
{
return;
}
calculated = new LDRImage();
await calculated.LoadFromBytes(HDRI.TransformChannel(channel), HDRI.Width, HDRI.Height);
ShowCalculated();
}
//initially called when this page is loaded, will recieve the 3 LDR images loaded from the previous page in a List as a parameter
protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
//loads the LDR images into the properities of this page
List <LDRImage> LDRImages = (List <LDRImage>)e.Parameter;
underExp = LDRImages[0];
regExp = LDRImages[1];
overExp = LDRImages[2];
//Renders the HDR image
Recalculate(this, null);
RecalculateButton.IsEnabled = false;
}
//Loads overexposed image
private async void LoadOverExp(object sender, TappedRoutedEventArgs e)
{
overExp = new LDRImage();
await overExp.Load();
if (overExp.GetBitmapImage() != null)
{
OverExp.Source = overExp.GetBitmapImage();
OverExpText.Opacity = 0.0;
//activates the HDR rendering button if the other two images are loaded as well
if (regExp != null && underExp != null)
{
HDRButton.IsEnabled = true;
}
}
}
//------------------------------------------------------------------------//
//blends the 3 different exposures
//percent: percentage of underexposed pixels in the blend (float from 0 to 1)
//top: how much to blend in the top layer (float from 0 to 1)
public static void BlendOld
(float percent, float top, LDRImage underExp, LDRImage regExp, LDRImage overExp, out byte[] bytes)
{
bytes = new Byte[regExp.GetDecoder().PixelHeight *regExp.GetDecoder().PixelWidth * 4];
//will contain the calculated brightness of all pixels in the underexposed image
List <float> brightness = new List <float>();
// calcuates brightness for all pixels in the under exposed image,
// then stores these brightness values in the brightness list
for (int i = 0; i < underExp.GetDecoder().PixelHeight; i++)
{
for (int g = 0; g < underExp.GetDecoder().PixelWidth; g++)
{
int h = (i * (int)underExp.GetDecoder().PixelWidth + g) * 4;
float bright = (float)Math.Sqrt((.299 * (underExp.GetBytes()[h] * underExp.GetBytes()[h]) + .587 * (underExp.GetBytes()[h + 1] * underExp.GetBytes()[h + 1]) + .114 * (underExp.GetBytes()[h + 2] * underExp.GetBytes()[h + 2])));
brightness.Add(bright);
}
}
//sorts the brightness list from least to greatest
brightness.Sort();
// Using the percent argument, find the appropriate value within the
// sorted brightness array in order to come up with a partitioning
// value
int pixels = (int)underExp.GetDecoder().PixelWidth *(int)underExp.GetDecoder().PixelHeight;
int partitionIndex = (int)(percent * pixels);
float partition = brightness[partitionIndex];
// For each pixel in the overexposed image, find the corresponding underexposed
// image pixel and use the partitioning value in order to determine whether or
// not to replace it with the corresponding overexposed image pixel
for (int i = 0; i < overExp.GetDecoder().PixelHeight; i++)
{
for (int g = 0; g < overExp.GetDecoder().PixelWidth; g++)
{
int h = (i * (int)overExp.GetDecoder().PixelWidth + g) * 4;
if (partition < (float)Math.Sqrt((.299 * (underExp.GetBytes()[h] * underExp.GetBytes()[h]) + .587 * (underExp.GetBytes()[h + 1] * underExp.GetBytes()[h + 1]) + .114 * (underExp.GetBytes()[h + 2] * underExp.GetBytes()[h + 2]))))
{
for (int k = 0; k < 4; k++)
{
bytes[h + k] = underExp.GetBytes()[h + k];
}
}
else
{
for (int k = 0; k < 4; k++)
{
bytes[h + k] = overExp.GetBytes()[h + k];
}
}
}
}
// Blend the regular exposed image on top of the blended image
// using the top argument
for (int i = 0; i < regExp.GetDecoder().PixelHeight; i++)
{
for (int g = 0; g < regExp.GetDecoder().PixelWidth; g++)
{
int h = (i * (int)regExp.GetDecoder().PixelWidth + g) * 4;
for (int k = 0; k < 3; k++)
{
float avg = (regExp.GetBytes()[h + k] - bytes[h + k]) * top;
bytes[h + k] += (byte)avg;
}
}
}
}
