c#gdi+ image Processing

Http://www.cnblogs.com/BLoodMaster/archive/2010/03/20/1690726.html

Supported formats: BMP, GIF, JPEG, EXIF, PNG, TIFF, ICON, WMF, EMF, etc., covering almost all common formats

Image class:

1. The image class: Bitmap and Metafile classes provide an abstract base class for functionality.
2. Metafile class: Defines a graphical metafile that contains records describing a series of graphical operations that can be recorded (constructed) and replayed (displayed)
3. Bitmap class: Encapsulates a GDI + bitmap that consists of pixel data for a graphic image and its properties, and bitmap is an object used to process images defined by pixel data.

Common Properties and methods:

Name	Description
Public properties
Height	Gets the height of this image object.
Rawformat	Gets the format of this image object.
Size	Gets the width and height of this image object.
Width	Gets the width of this image object.
Public methods
GetPixel	Gets the color of the specified pixel in this bitmap.
Maketransparent	Makes the default transparent color transparent to this bitmap.
RotateFlip	Rotate, flip, or colleague rotate and flip an image object.
Save	Saves the image object to the specified stream object in the specified format.
SetPixel	Sets the color of the specified pixel in the bitmap object.
Setpropertyitem	Sets the specified property item to the specified value.
Setresolution	Sets the resolution for this bitmap.

To construct an bitmap instance:

Public Bitmap (Image); Create from an existing image, which can be replaced by equivalent parameters public Bitmap (int, int); Public Bitmap (Image, BOOL);//bool: Color correction flag bit Public Bitmap (Type, string);//type the class that extracts the resource, string resource name public Bitmap (int, int, pixelformat);//PixelFormat Pixel format Enumeration public Bitmap (int, int, graphics);//Graphics Set resolution public Bitmap (int, int, int stride, PixelFormat, INTPTR);//Stride Specifies an integer that is the byte offset between the beginning of the adjacent scan line. The value passed to this parameter must be a multiple of 4. IntPtr pointer to a byte array that contains the pixel data.

PixelFormat enumeration:

Name	Description
Dontcare = 0	No pixel format specified
Undefined = 0	Pixel format Not defined
Max = 15	The maximum value of this enumeration
Indexed = 65536	The pixel data contains the color index values, which means that the values are the indexes of the colors in the system color table, not the individual color values.
Gdi = 131072	Pixel data contains GDI colors
format16bpprgb555 = 135173	The specified format is 16 bits per pixel, and the red, green, and blue components each use 5 bits. The remaining 1 bits not used
format16bpprgb565 = 135174	The specified format is 16 bits per pixel, the red component uses 5 bits, the green component uses 6 bits, and the blue component uses 5 bits
Format24bpprgb = 137224	The specified format is 24 bits per pixel, and the red, green, and blue components each use 8 bits
Format32bpprgb = 139273	The specified format is 32 bits per pixel, and the red, green, and blue components each use 8 bits. The remaining 8 bits not used
format1bppindexed = 196865	Specifies that the pixel format is 1 bits per pixel and specifies that it uses indexed colors. So there are two colors in the color table
format4bppindexed = 197634	Specifies a 4-bit format per pixel and an index has been created
format8bppindexed = 198659	The specified format is 8 bits per pixel and an index has been created. So there are 256 colors in the color table
Alpha = 262144	The pixel data contains an alpha value that has not been made from the left multiply
format16bppargb1555 = 397319	The pixel format is 16 bits per pixel. This color information specifies 32,768 tones, 5 bits red, 5 bits green, 5 bits blue, and 1 bits is alpha.
Palpha = 524288	The pixel format contains the alpha value from the left multiply
Format32bpppargb = 925707	The specified format is 32 bits per pixel, and the alpha, red, green, and blue components each use 8 bits. The red, green, and blue components are left-multiplied according to the alpha component
Extended = 1048576	Keep
Format16bppgrayscale = 1052676	The pixel format is 16 bits per pixel. This color information specifies 65536 shades of gray
Format48bpprgb = 1060876	The specified format is 48 bits per pixel, and the red, green, and blue components each use 16 bits
Format64bpppargb = 1851406	The specified format is 64 bits per pixel, and the alpha, red, green, and blue components each use 16 bits. The red, green, and blue components are left-multiplied according to the alpha component
Canonical = 2097152	The default pixel format, 32 bits per pixel. This format specifies 24-bit color depth and a 8-bit alpha channel
Format32bppargb = 2498570	The specified format is 32 bits per pixel; alpha, red, green, and blue components each use 8 bits
Format64bppargb = 3424269	The specified format is 64 bits per pixel; alpha, red, green, and blue components each use 16 bits

Input to the image:

1. The Image property setting in the Properties dialog box when the form is designed
2. In-Program dialog box input

In-Program dialog box input: (example)

Open the dialog box:

OpenFileDialog Ofdlg = new OpenFileDialog (); Ofdlg. Filter = "BMP File (*.bmp) |*.bmp"; if (Ofdlg. ShowDialog () = = DialogResult.OK) { Bitmap image = New Bitmap (Ofdlg. FileName); }

Save dialog box:

String str; Bitmap box1 = new Bitmap (picturebox1.image); SaveFileDialog Sfdlg = new SaveFileDialog (); Sfdlg. Filter = "BMP file (*. BMP) |*. bmp| All File (*. *) |*.* "; Sfdlg. ShowDialog (); str = Sfdlg. FileName; Box1. Save (str);

For the use of OpenFileDialog and SaveFileDialog, refer to the MSDN related sections.

Conversion of image formats:

The second parameter in the Save method of the bitmap object specifies the format in which the image is saved. Modify this parameter to convert the image format.

Supported formats for bitmaps: Imaging.imageformat

Name	Description
Bmp	Gets the bitmap image format (BMP).
Emf	Gets the enhanced Windows Metafile image format (EMF).
Exif	Gets the exchangeable image file (Exif) format.
Gif	Gets the Graphics Interchange Format (GIF) image format.
Guid	Gets the GUID structure that represents this Imageforma object.
Icon	Gets the Windows Icon image format.
Jpeg	Gets the joint Image Expert Group (JPEG) image format.
Memorybmp	Gets the memory bitmap image format.
Png	Gets the web-Portable Network Graphics (PNG) image format.
Tiff	Gets the label image file format (TIFF) image format.
Wmf	Gets the Windows Metafile (WMF) image format.

Image copy and paste clipboard:

Common methods:

Name	Description
Clear	Removes all data from the Clipboard.
Containsdata	Indicates whether the Clipboard has data in the specified format, or can be converted to this format.
ContainsImage	Indicates whether there is a Bitmap format in the Clipboard or data that can be converted to this format.
ContainsText	is overloaded. Indicates whether text data exists in the Clipboard.
GetData	Retrieves the data in the specified format from the Clipboard.
GetDataObject	Retrieves data that is currently on the system Clipboard.
Getfiledroplist	Retrieves a collection of file names from the Clipboard.
GetImage	Retrieves the image on the Clipboard.
GetText	is overloaded. Retrieves text data from the Clipboard.
Setaudio	is overloaded. Adds data from the Waveaudio format to the Clipboard.
SetData	Adds data from the specified format to the Clipboard.
SetDataObject	is overloaded. Place the data on the system Clipboard.
SetImage	Adds an image of the bitmap format to the Clipboard.
SetText	is overloaded. Adds text data to the Clipboard.

Step: Place the data on the Clipboard. Retrieves data from the Clipboard.

1. Place data on the Clipboard

You can place data on the Clipboard through the SetDataObject method, the SetDataObject method has the following three forms of definition:

public static void SetDataObject (object); public static void SetDataObject (object, bool);//bool when the program exits, remains on the clipboard public static void SetDataObject (object, bool, int, int);//number of times and milliseconds between attempts and two attempts

1. Retrieving data from the Clipboard

public static IDataObject GetDataObject ();

Color processing of images:

Adjust resolution: The so-called resolution refers to the screen of the resolution, by how many pixels, the larger the value, the more clear the image.

Algorithm Description: Transform the image of the n*n resolution into a m*m resolution method is to divide the source image into n/m*n/m sub-image block, and then the n/m*n/m sub-image block of all the pixels of the color of f (i,j) to set the color value to achieve the purpose of reducing the resolution.

Adjust color:

Ashing: Algorithm Description: The color value of color image pixels is decomposed into three primary colors R, G, B, the average of the values, and then use the SetPixel method to generate an image with the average parameter.

Gray-scale image processing: According to the specific input and output gray-scale conversion relationship, enhance the image grayscale, processing the image of the medium gray value increases, the image becomes bright.

Color name	R value	G value	B Value
Red	255	0	0
Blue	0	0	255
Green	0	255	0
White	255	255	255
Yellow	255	255	0
Black	0	0	0
Green	0	255	255
Magenta	255	0	255

Color table: (RGB)

c#gdi+ image Processing