C# Image Resizer with Canvas Handler

Question

I'm incredibly new to C# (just started today)

I need to be able to make a C# Image resizer with a canvas handler. For example a 500 x 500 image needs to retain its aspect ration. it will be getting resized to 1024x500. To do this it will remain 500x500 but then fill the rest of the space with white space (the canvas).

I will also be resizing the same original image to 300 x 500, where the image will again retain its 1:1 ration and be resized to 300x300 and the remaining space again used as canvas white space.

Can anybody help me to produce a C# console application for this, that I can understand?

Here is what I have managed to find that I could reasonably understand (due to nice commenting).

What I find with code is that I can read it, but when it comes to me actually writing some I just fall apart. I mainly do HTML and CSS. Starting to branch out into JQuery and C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Drawing;
using System.Drawing.Imaging;

namespace ImageResizer
{

    class ImageResize
    {
        static void Main(string[] args)
        {
        }
        public void ResizeImage(string OriginalFile, string NewFile, int NewWidth, int MaxHeight, bool OnlyResizeIfWider)
        {
            System.Drawing.Image FullsizeImage = System.Drawing.Image.FromFile(OriginalFile);

            // Prevent using images internal thumbnail

            FullsizeImage.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone);

            FullsizeImage.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone);

            if (OnlyResizeIfWider)
                {

                    if (FullsizeImage.Width <= NewWidth)
                {
                NewWidth = FullsizeImage.Width;
                }
                }

            int NewHeight = FullsizeImage.Height * NewWidth / FullsizeImage.Width;
            if (NewHeight > MaxHeight)
            {
            // Resize with height instead
                NewWidth = FullsizeImage.Width * MaxHeight / FullsizeImage.Height;
                NewHeight = MaxHeight;
            }
            System.Drawing.Image NewImage = FullsizeImage.GetThumbnailImage(NewWidth, NewHeight, null, IntPtr.Zero);

            // Clear handle to original file so that we can overwrite it if necessary
            FullsizeImage.Dispose();

            // Save resized picture
        NewImage.Save(NewFile);
        }
    }
}

Answer 1

Try To Go For This>>

private void resizeImage(string path, string originalFilename, 
                     /* note changed names */
                     int canvasWidth, int canvasHeight, 
                     /* new */
                     int originalWidth, int originalHeight)
{
    Image image = Image.FromFile(path + originalFilename);

    System.Drawing.Image thumbnail = 
        new Bitmap(canvasWidth, canvasHeight); // changed parm names
    System.Drawing.Graphics graphic = 
                 System.Drawing.Graphics.FromImage(thumbnail);

    graphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
    graphic.SmoothingMode = SmoothingMode.HighQuality;
    graphic.PixelOffsetMode = PixelOffsetMode.HighQuality;
    graphic.CompositingQuality = CompositingQuality.HighQuality;

    /* ------------------ new code --------------- */

    // Figure out the ratio
    double ratioX = (double) canvasWidth / (double) originalWidth;
    double ratioY = (double) canvasHeight / (double) originalHeight;
    // use whichever multiplier is smaller
    double ratio = ratioX < ratioY ? ratioX : ratioY;

    // now we can get the new height and width
    int newHeight = Convert.ToInt32(originalHeight * ratio);
    int newWidth = Convert.ToInt32(originalWidth * ratio);

    // Now calculate the X,Y position of the upper-left corner 
    // (one of these will always be zero)
    int posX = Convert.ToInt32((canvasWidth - (originalWidth * ratio)) / 2);
    int posY = Convert.ToInt32((canvasHeight - (originalHeight * ratio)) / 2);

    graphic.Clear(Color.White); // white padding
    graphic.DrawImage(image, posX, posY, newWidth, newHeight);

    /* ------------- end new code ---------------- */

    System.Drawing.Imaging.ImageCodecInfo[] info =
                     ImageCodecInfo.GetImageEncoders();
    EncoderParameters encoderParameters;
    encoderParameters = new EncoderParameters(1);
    encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality,
                     100L);            
    thumbnail.Save(path + width + "." + originalFilename, info[1], 
                     encoderParameters);
}