ImageHelper
Provides utility methods for image manipulation, processing, and conversion operations.
Definition
Namespace:Telerik.WinControls
Assembly:Telerik.WinControls.dll
Syntax:
public static class ImageHelperInheritance: objectImageHelper
Methods
Applies a uniform alpha (transparency) value to all pixels in the specified bitmap.
public static void ApplyAlpha(Bitmap bitmap, float fAlpha)The bitmap to modify. Must be in 32bpp ARGB format.
fAlphafloatThe alpha value to apply, ranging from 0.0 (fully transparent) to 1.0 (fully opaque).
Directly modifies the alpha channel of each pixel using unsafe code for optimal performance. The bitmap must be in 32bpp ARGB format. Commonly used for fade effects and transparency adjustments.
Applies a brush-based alpha mask to a bitmap, modifying the transparency of pixels based on the brush pattern.
public static void ApplyMask(Bitmap bitmap, Brush brush)The bitmap to apply the mask to.
brushBrushThe brush defining the alpha mask pattern. The brush's color values determine the transparency.
This method creates a temporary bitmap filled with the specified brush pattern, then uses the red channel values from this pattern as alpha values for the original bitmap. This allows for complex transparency effects based on gradients, patterns, or solid colors.
The masking process:
- Creates a temporary bitmap the same size as the original
- Fills the temporary bitmap with the brush pattern
- Uses the red channel values as alpha channel values for each corresponding pixel
This is useful for creating fade effects, vignettes, and complex transparency patterns.
Copies given image to the clipboard. Different applications understand different image formats, so this method applies the three most common image formats to the data object - Bitmap, PNG and DIB.
Crops a rectangular region from a bitmap and returns it as a new bitmap with high-quality rendering.
public static Bitmap Crop(Bitmap image, Rectangle cropRectangle)The source bitmap to crop from.
cropRectangleRectangleThe rectangular region to extract from the source image, in pixel coordinates.
Returns:A new Bitmap containing the cropped region, with dimensions matching the crop rectangle.
This method creates a new bitmap with the exact dimensions of the crop rectangle and draws the specified region from the source image using high-quality rendering settings:
- Anti-aliased smoothing for clean edges
- High-quality bicubic interpolation for smooth scaling
- High-quality pixel offset mode for precise positioning
The crop rectangle coordinates are relative to the source image. If the rectangle extends beyond the source image boundaries, the out-of-bounds areas will be filled with transparent pixels.
The caller is responsible for disposing of the returned bitmap when no longer needed.
Gets image from the clipboard and preserves pixel transparency. If there is no image data in the clipboard, returns null.
Retrieves an image from the given clipboard data object, in the order PNG, DIB, Bitmap, Image object.
public static Bitmap GetClipboardImage(DataObject clipboardData)The clipboard data.
Returns:The extracted image, or null if no supported image type was found.