c#: change image DPI using MagickImage and resize the image

Question

i am using MagickImage to change Dpi of an image but it doesn't work

MagickNET.SetGhostscriptDirectory(System.IO.Directory.GetCurrentDirectory());
        MagickReadSettings settings = new MagickReadSettings();
        settings.Density = new Density(72, 72);
        using (MagickImage image = new MagickImage(@"C:\Users\User\AppData\Local\Temp\Chapter 4\Figure 4-1.tif", settings))
        {
            image.Write(@"C:\Users\User\AppData\Local\Temp\Chapter 4\Figure 4-1.jpg");
        }

or if this doesn't work

is there a way to resize the image like what the photoshop did

example the image with 300 dPi have a w1200xh788 size

and using photoshop. i changed the dpi to 72 and it creates a w288xh189

how can i programmatically do this. thank you

yes i already read that. but how do i know the size of the image in 72 dpi? — pdf asker, Sep 27 '16 at 05:26
You can right click on image and go to properties, select details tab and you are able to see size of that image. — Chirag, Sep 27 '16 at 05:44
sir im doing it programatically, example the image with 300 dPi have a w1200xh788 size and using photoshop. i changed the dpi to 72 and it creates a w288xh189 — pdf asker, Sep 27 '16 at 05:46
you can calculate it then, like (1200*72)/300 will return 288, same way (788*72)/300 will return 189. — Chirag, Sep 27 '16 at 05:50
the same i have told you in previous comment. anyway Enjoy.(make my comment helpful as well) — Chirag, Sep 27 '16 at 06:04
@Chirag can you post your comment as an answer. Thank you. so that i will mark my question solved thanks — pdf asker, Sep 27 '16 at 07:22

score 0 · Answer 1 · answered Sep 27 '16 at 07:45

You can do as following :

using System;

    namespace ImageDPI
    {
        public class Program
        {
            public static void Main(string[] args)
            {
                int Aw, Ah, Rw, Rh, Adpi, Rdpi;

                Aw = 1200;
                Ah = 788;

                Adpi = 300;
                Rdpi = 72;

                Rw= (Aw * Rdpi) / Adpi;
                Rh= (Ah * Rdpi) / Adpi;

                Console.WriteLine(Rw);
                Console.WriteLine(Rh);


            }
        }
    }

c#: change image DPI using MagickImage and resize the image

1 Answers1