FrameworkExtensions.System.Drawing 1.0.0.70

Extensions to System.Drawing

Extension methods for System.Drawing types (bitmaps, images, colors, graphics).

Extension Methods

Bitmap Extensions (Bitmap)

Bitmap Locking

• Lock(...) - Lock bitmap for direct pixel access (8 overloads for different combinations)
  • Lock() - Lock entire bitmap with ReadWrite mode
  • Lock(Rectangle) - Lock region
  • Lock(ImageLockMode) - Lock with specific mode
  • Lock(PixelFormat) - Lock with specific format
  • Lock(Rectangle, ImageLockMode)
  • Lock(Rectangle, PixelFormat)
  • Lock(ImageLockMode, PixelFormat)
  • Lock(Rectangle, ImageLockMode, PixelFormat) - Full control
  • Returns format-specific IBitmapLocker implementation

Transformations

• ConvertPixelFormat(PixelFormat) - Convert bitmap to different pixel format
• Crop(Rectangle, PixelFormat = DontCare) - Extract region from bitmap
• Resize(int width, int height, InterpolationMode = Bicubic) - Resize bitmap
• Rotated(float angle, Point? center = null) - Create rotated copy of bitmap
• RotateInplace(float angle, Point? center = null) - Rotate bitmap in-place
• RotateTo(Bitmap target, float angle, Point? center = null) - Rotate to target bitmap

Image Extensions (Image)

Multi-Page Support

• GetPageAt(int page) - Get specific page from multi-page image (e.g., TIFF)
• GetPageCount() - Get total number of pages in image

Save Operations

• SaveToPng(FileInfo/string) - Save image as PNG
• SaveToTiff(string) - Save image as TIFF
• SaveToJpeg(string/Stream, double quality = 1) - Save as JPEG with quality (0.0-1.0)

Conversions

• ToIcon(int targetRes = 0) - Convert image to Icon
• ToBase64DataUri() - Convert to Base64 data URI string
• FromBase64DataUri(string) (static-like extension on string) - Create image from Base64 data URI

Image Processing

• MakeGrayscale() - Convert image to grayscale
• Threshold(byte threshold = 127) - Apply threshold filter (black/white)
• ApplyPixelProcessor(Func<Color, Color> processor) - Apply custom pixel transformation function
• MirrorAlongX() - Mirror horizontally
• MirrorAlongY() - Mirror vertically
• Resize(int longSide) - Resize to fit within square, keep aspect
• Resize(int longSide, Color fillColor) - Resize with fill color
• Resize(int width, int height, bool keepAspect = true, Color? fillColor = null) - Resize with options
• Resize(int width = -1, int height = -1, InterpolationMode = Default) - Resize with interpolation
• Rotate(float angle) - Rotate image by angle
• GetRectangle(Rectangle) - Extract rectangular region
• ReplaceColorWithTransparency(Color) - Replace specific color with transparency

Color Extensions (Color)

Color Space Conversion

• Rgb / RgbNormalized - Convert to RGB color space
• Hsl / HslNormalized - Convert to HSL (Hue, Saturation, Lightness)
• Hsv / HsvNormalized - Convert to HSV (Hue, Saturation, Value)
• Hwb / HwbNormalized - Convert to HWB (Hue, Whiteness, Blackness)
• Cmyk / CmykNormalized - Convert to CMYK (Cyan, Magenta, Yellow, Key)
• Xyz / XyzNormalized - Convert to CIE XYZ tristimulus values
• Lab / LabNormalized - Convert to CIE Lab* perceptual color space
• Yuv / YuvNormalized - Convert to YUV (Luma + chrominance)
• YCbCr / YCbCrNormalized - Convert to YCbCr digital video encoding
• Din99 / Din99Normalized - Convert to DIN99 (DIN 6176) perceptual space

Color Comparison

• IsLike(Color other, byte luminanceDelta = 24, byte chromaUDelta = 7, byte chromaVDelta = 6) - Compare colors in YUV space with tolerance
• IsLikeNaive(Color other, int tolerance = 2) - Simple RGB comparison with tolerance

Color Blending

• BlendWith(Color other, float current, float max) - Interpolate between two colors

Graphics Extensions (Graphics)

• DrawString(float x, float y, string text, Font font, Brush brush, ContentAlignment anchor) - Draw text with anchor positioning
• DrawCross(float/int x, float/int y, float/int size, Pen pen) - Draw cross marker (4 overloads including Point/PointF)
• DrawCircle(Pen pen, float centerX, float centerY, float radius) - Draw circle outline
• FillCircle(Brush brush, float centerX, float centerY, float radius) - Draw filled circle

Rectangle Extensions (Rectangle)

• MultiplyBy(int factor) - Scale rectangle uniformly
• MultiplyBy(int xfactor, int yfactor) - Scale rectangle with different X/Y factors
• CollidesWith(Rectangle/RectangleF) - Check rectangle collision
• CollidesWith(Point/PointF) - Check if point is inside
• CollidesWith(int x, int y) / CollidesWith(float x, float y) - Check if coordinates are inside
• Center() - Get center point
• SetLeft/SetRight/SetTop/SetBottom(int) - Create new rectangle with modified edge

RectangleF Extensions (RectangleF)

(Similar methods to Rectangle, for floating-point rectangles)

Size Extensions (Size)

• Center() - Get center point

Point Extensions (Point)

(Generated from T4 template - numeric operations on points)

FileInfo Extensions (FileInfo)

• GetIcon(bool smallIcon = false, bool linkOverlay = false) - Get Windows shell icon for file
  • Uses native SHGetFileInfo API

Custom Types

IBitmapLocker Interface

Format-specific bitmap pixel access implementations:

• ARGB32BitmapLocker - 32-bit ARGB (Format32bppArgb)
• RGB32BitmapLocker - 32-bit RGB (Format32bppRgb)
• RGB24BitmapLocker - 24-bit RGB (Format24bppRgb)
• RGB565BitmapLocker - 16-bit RGB 565 (Format16bppRgb565)
• ARGB1555BitmapLocker - 16-bit ARGB 1555 (Format16bppArgb1555)
• Gray16BitmapLocker - 16-bit grayscale (Format16bppGrayScale)
• RGB555BitmapLocker - 16-bit RGB 555 (Format16bppRgb555)
• Indexed8BitmapLocker - 8-bit indexed (Format8bppIndexed)
• IndexedBitmapLocker - 1-bit and 4-bit indexed (Format1bppIndexed, Format4bppIndexed)
• UnsupportedDrawingBitmapLocker - Fallback for unsupported formats

Each locker provides optimized pixel access for its specific format.

Color Spaces (System.Drawing.ColorSpaces)

A comprehensive color space conversion and comparison library with zero-cost generic abstractions.

Color Space Types

Distance Calculators (System.Drawing.ColorSpaces.Distances)

All calculators also have *Squared variants for faster comparisons.

Palette Search

using System.Drawing.ColorSpaces;
using System.Drawing.ColorSpaces.Distances;

// Find closest color in palette using perceptual distance
var palette = new[] { Color.Red, Color.Green, Color.Blue };
var index = PaletteSearch.GetMostSimilarColorIndex<CIEDE2000Distance>(palette, targetColor);

// Use any color space for comparison
var index = PaletteSearch.GetMostSimilarColorIndex<EuclideanDistance<Yuv>>(palette, targetColor);

// Cache lookups for repeated queries (e.g., image processing)
var cached = new CachedPalette<EuclideanDistance<Yuv>>(palette);
foreach (var pixel in imagePixels) {
  var paletteIndex = cached.GetIndex(pixel);  // O(1) after first lookup
}

Color Interpolation (System.Drawing.ColorSpaces.Interpolation)

using System.Drawing.ColorSpaces.Interpolation;

// Interpolate in perceptual Lab space
var lerp = new ColorLerp<Lab>();
var midpoint = lerp.Lerp(color1, color2, 0.5f);

// Create smooth gradients
var gradient = new ColorGradient<Hsl>(Color.Red, Color.Blue);
var colors = gradient.GetColors(10);  // 10 evenly-spaced colors

Installation

dotnet add package FrameworkExtensions.System.Drawing

License

LGPL 3.0 or later - See LICENSE for details