C # proportional scaling of images,

C # proportional scaling of images,

Tool code:

Using System; using System. collections. generic; using System. drawing; using System. drawing. drawing2D; using System. drawing. imaging; using System. linq; using System. text; using System. threading. tasks; namespace ZoomImage. utils {/// <summary> /// image scaling /// </summary> public class ZoomImageUtil {/// <summary> /// image scaling /// </ summary> /// <param name = "bmp"> image </param> /// <param name = "width"> Target width, if the value is 0, the width is scaled proportionally </param> /// <param name = "height"> the target length. If the value is 0, indicates proportional length scaling </param> public static Bitmap GetThumbnail (Bitmap bmp, int width, int height) {if (width = 0) {width = height * bmp. width/bmp. height;} if (height = 0) {height = width * bmp. height/bmp. width;} Image imgSource = bmp; Bitmap outBmp = new Bitmap (width, height); Graphics g = Graphics. fromImage (outBmp); g. clear (Color. transparent); // you can specify the quality of the canvas. compositingQuality = CompositingQuality. highQuality; g. smoothingMode = SmoothingMode. highQuality; g. interpolationMode = InterpolationMode. highQualityBicubic; g. drawImage (imgSource, new Rectangle (0, 0, width, height + 1), 0, 0, imgSource. width, imgSource. height, GraphicsUnit. pixel); g. dispose (); imgSource. dispose (); bmp. dispose (); return outBmp ;}}}View Code

Example:

Using System; using System. collections. generic; using System. componentModel; using System. data; using System. drawing; using System. IO; using System. linq; using System. text; using System. threading; using System. threading. tasks; using System. windows. forms; using ZoomImage. utils; namespace ZoomImage {public partial class Form1: Form {public Form1 () {InitializeComponent ();} private void Form1_Load (object sende R, EventArgs e) {openFileDialog1.Multiselect = true;} private void txtWidth_KeyPress (object sender, KeyPressEventArgs e) {if (e. KeyChar! = 8 &&! Char. IsDigit (e. KeyChar) {e. Handled = true ;}} private void txtHeight_KeyPress (object sender, KeyPressEventArgs e) {if (e. KeyChar! = 8 &&! Char. isDigit (e. keyChar) {e. handled = true ;}} private void btnSelectImage_Click (object sender, EventArgs e) {try {if (txtWidth. text = "" & txtHeight. text = "") {return;} if (openFileDialog1.ShowDialog () = DialogResult. OK) {Task. factory. startNew () => {string path = Path. getDirectoryName (openFileDialog1.FileNames [0]) + "\ NewImage \"; int I = 0; foreach (string fileName in openFileDialo G1.FileNames) {Bitmap bmp = ZoomImageUtil. GetThumbnail (new Bitmap (fileName), Convert. ToInt32 (txtWidth. Text = ""? "0": txtWidth. Text), Convert. ToInt32 (txtHeight. Text = ""? "0": txtHeight. Text); if (! Directory. exists (path) {Directory. createDirectory (path);} File. delete (path + Path. getFileName (fileName); bmp. save (path + Path. getFileName (fileName); this. invoke (new InvokeDelegate () => {lblProgress. text = string. format ("Progress: {1}/{0}", openFileDialog1.FileNames. length, ++ I) ;})); Thread. sleep (1);} MessageBox. show ("successful! ") ;};}} Catch (Exception ex) {MessageBox. show (ex. message) ;}}/// <summary> /// delegate the cross-thread access control /// </summary> public delegate void InvokeDelegate ();}View Code