How to draw an image very fast from a file in the stream format?

[mina2040]

Hi there,

I would like to display thousands of image files on the screen. I am using the following code to display them:

Bitmap Origbmp = new Bitmap(Filename);
bmp = new Bitmap(Origbmp.Width, Origbmp.Height, PixelFormat.Format32bppArgb);
Graphics gr = Graphics.FromImage(bmp);
gr.DrawImage(Origbmp, 0, 0, Origbmp.Width, Origbmp.Height);

but now the files are in a special format that cannot be displayed using the above code. So I have to load the file into memory, change some particular bytes and then pass them to the Origbmp. so I do as follows:

//read the file into a stream
byte[] fileInBytes = File.ReadAllBytes(Filename);
Stream fileInStream = new MemoryStream(fileInBytes);
fileInStream.Write(Newbytes, pos,len);
Bitmap Origbmp = new Bitmap(fileInStream);
bmp = new Bitmap(Origbmp.Width, Origbmp.Height, PixelFormat.Format32bppArgb);
Graphics gr = Graphics.FromImage(bmp);
gr.DrawImage(Origbmp, 0, 0, Origbmp.Width, Origbmp.Height);

is there anyway to do it faster? How can I read the file directly to a stream rather than first reading it to a byte array and then to a stream?
Is there any other way to do the whole thing more efficient and faster?

[Aimee Bailey]

If the intention is to modify pixels on the bitmap before it's drawn, wouldn't you be better using the Graphics library?

Aimee.

[mina2040]

Hi Aimee,

thanks for your post. The intention is to modify some buyes of the file before drawing it on the screen. Has this make it more clear?

[mzmishra]

I did something like below in my code to display image in a webpage.

byte[] bArrImage = null;
MemoryStream memoryStream = null;
System.Drawing.Image Image = null;
bArrImage = //code to get the image from database
memoryStream = new MemoryStream(bArrImage);
Image = Bitmap.FromStream(memoryStream);