goGud goGud - 1 year ago 264
C# Question

How to create bitmap from byte array?

I searched all question about byte array but i always failed. I have never coded c# i am new in this side. Could you help me how to make image file from byte array.

Here is my function which stores byte in array named


public void imageReady( byte[] imageData, int fWidth, int fHeight))

Answer Source

Guys thank you for your help. I think all of this answers works. However i think my byte array contains raw bytes. That's why all of those solutions didnt work for my code.

However i found a solution. Maybe this solution helps other coders who have problem like mine.

static byte[] PadLines(byte[] bytes, int rows, int columns) {
   int currentStride = columns; // 3
   int newStride = columns;  // 4
   byte[] newBytes = new byte[newStride * rows];
   for (int i = 0; i < rows; i++)
       Buffer.BlockCopy(bytes, currentStride * i, newBytes, newStride * i, currentStride);
   return newBytes;

 int columns = imageWidth;
 int rows = imageHeight;
 int stride = columns;
 byte[] newbytes = PadLines(imageData, rows, columns);

 Bitmap im = new Bitmap(columns, rows, stride, 
          Marshal.UnsafeAddrOfPinnedArrayElement(newbytes, 0));


This solutions works for 8bit 256 bpp (Format8bppIndexed). If your image has another format you should change PixelFormat .

And there is a problem with colors right now. As soon as i solved this one i will edit my answer for other users.

*PS = I am not sure about stride value but for 8bit it should be equal to columns.

And also this function Works for me.. This function copies 8 bit greyscale image into a 32bit layout.

public void SaveBitmap(string fileName, int width, int height, byte[] imageData)

            byte[] data = new byte[width * height * 4];

            int o = 0;

            for (int i = 0; i < width * height; i++)
                byte value = imageData[i];

                data[o++] = value;
                data[o++] = value;
                data[o++] = value;
                data[o++] = 0; 

                fixed (byte* ptr = data)

                    using (Bitmap image = new Bitmap(width, height, width * 4,
                                PixelFormat.Format32bppRgb, new IntPtr(ptr)))

                        image.Save(Path.ChangeExtension(fileName, ".jpg"));
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