protected override RequestedAction PreRenderImage(ImageState state)
{
if (state == null || !state.Data.ContainsKey(DataKey))
{
return(RequestedAction.None);
}
var data = (AutoCropState)state.Data[DataKey];
var settings = (AutoCropSettings)state.Data[SettingsKey];
var targetBox = data.TargetDimensions;
var instructions = data.Instructions;
var size = instructions.Size;
if (data.ShouldPreRender)
{
// In this case another image should be rendered
// This can be done by using the preRenderBitmap in the image state
// If there isn't one already, or if it is of differing size, override it
if (state.preRenderBitmap != null && state.preRenderBitmap.Size != size)
{
state.preRenderBitmap.Dispose();
state.preRenderBitmap = null;
}
if (state.preRenderBitmap == null)
{
state.preRenderBitmap = new Bitmap(size.Width, size.Height, state.sourceBitmap.PixelFormat);
}
// Since all bitmaps are created with 0 values after allocation
// The proper background color needs to be pre-filled
if (data.BytesPerPixel == 3)
{
Raw.FillRgb(state.preRenderBitmap, data.BorderColor);
}
else if (data.BytesPerPixel == 4)
{
Raw.FillRgba(state.preRenderBitmap, data.BorderColor);
}
// Copy pixels from original
Raw.Copy(state.sourceBitmap, instructions.Target, state.preRenderBitmap, instructions.Translate);
// Set the ImageResizer copyRect
// This will crop the image in the render step
state.copyRect = new RectangleF(0, 0, size.Width, size.Height);
}
else
{
state.copyRect = new RectangleF(state.copyRect.X + targetBox.X, state.copyRect.Y + targetBox.Y, state.copyRect.Width, state.copyRect.Height);
}
if (state == null || !settings.Debug)
{
return(RequestedAction.None);
}
try
{
var preRenderBitmap = state.preRenderBitmap ?? new Bitmap(state.sourceBitmap);
if (settings.Method == AutoCropMethod.Edge)
{
// Display graphics as analyzer sees it.
preRenderBitmap = Filter.Sobel(preRenderBitmap);
}
else
{
preRenderBitmap = Filter.Buckets(preRenderBitmap);
}
// Establish a drawing canvas
using (var graphics = Graphics.FromImage(preRenderBitmap))
{
graphics.SmoothingMode = SmoothingMode.AntiAlias;
// Render the detected bounding box in red
var brushSize = 2 * (1 / instructions.Scale);
using (var pen = new Pen(Color.Red, (int)brushSize))
{
var rectangle = instructions.Source;
if (data.ShouldPreRender)
{
var padding = data.Padding;
var width = size.Width - padding.Width * 2;
var height = size.Height - padding.Height * 2;
var offsetX = padding.Width;
var offsetY = padding.Height;
rectangle = new Rectangle(offsetX, offsetY, width, height);
}
graphics.DrawRectangle(pen, rectangle);
}
}
if (state.preRenderBitmap != null)
{
state.preRenderBitmap.Dispose();
}
state.preRenderBitmap = preRenderBitmap;
}
catch (Exception)
{
// ignore
}
return(RequestedAction.None);
}
