Type Bitmap from a c# code not recognized in unity 2018

Question

I have visual studio 2017 and unity 2018. I'm trying to work with a script of a neural network to be attached to an object in the scene that, in order to be trained, makes use of the bitmap class. The problem is that the console of unity gives me the error: 'The type or namespace 'Bitmap' could not be found'. Does anyone know how I can do ? I'm making use of the directives :

using System;

using System.Collections.Generic;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Threading.Tasks; 

Here is the script:  

 

     public void Train()
            {
                //Convert to Pixel Array
                Bitmap img = new Bitmap(@"C:\Users\Marc\Desktop\media\resoureces\sites.jpeg");
                double[,,] pixelvalues = new double[3, img.Width, img.Height];
                for (int i = 0; i < img.Width; i++)
                {
                    for (int j = 0; j < img.Height; j++)
                    {
                        Color pixel = img.GetPixel(i, j);
                        pixelvalues[0, i, j] = pixel.R;
                        pixelvalues[1, i, j] = pixel.G;
                        pixelvalues[2, i, j] = pixel.B;
                        //if (pixel == *somecondition *)
                        //{
                        //    **Store pixel here in a array or list or whatever**
                        //}
                    }
                }

AFAIK, you can't use `System.Drawing` from within Unity. Do you actually need to use `System.Drawing.Bitmap` and not a `Byte[]` or `UInt32[]` array? — Dai, Jan 18 '21 at 18:49
`Bitmap.GetPixel` is very slow, btw - if you use a raw array (or `unsafe` array with `LockBits`) you'll get significantly faster performance, btw. — Dai, Jan 18 '21 at 18:51
Also, why are you using a 3D array of `double`? RGB arrays have integral values. Also note that multi-dimensional arrays in .NET are also slower than they should be: https://stackoverflow.com/questions/468832/why-are-multi-dimensional-arrays-in-net-slower-than-normal-arrays — Dai, Jan 18 '21 at 18:52
I need to use a bitmap or something from which I can extract pixel values for the convolutional neural network. Do you know how I can do ? — MarcDed, Jan 18 '21 at 18:54
Then use an external program to save `sites.jpg` to a raw raster representation on-disk *first* and then read that into a `Byte[]` or `UInt32[]` - you don't need `System.Drawing` in Unity for that. — Dai, Jan 18 '21 at 20:14

score 0 · Accepted Answer · answered Jan 19 '21 at 05:16

Find System.Drawing.dll in your Unity Editor Install Folder.

C:\UnityEditors\2018.4.28f1\Editor\Data\MonoBleedingEdge\lib\mono\gac\System.Drawing\4.0.0.0__b03f5f7f11d50a3a\System.Drawing.dll

Move this dll into your Assets/Plugins folder:

Make sure that you uncheck Validate References:

Success:

Type Bitmap from a c# code not recognized in unity 2018

1 Answers1