将图像读取到字节数组并进行更改

Question

I am trying to work with MemoryStream in C#. So, I do converting Image to byte array and byte array to Image. Like this

var bytes = File.ReadAllBytes("1.jpg");
var ms = new MemoryStream(bytes, true);
var image = Image.FromStream(ms);
pictureBox1.Image = image;

It works fine (displaying image in picture box). But when i try to change byte array

bytes[0] = 254

It throws exception invalid parameter. So, how I can change byte array or write bytes to stream? ms.WriteByte not works. Thanks

Answer 1

JPEG (JPG) file is compressed representation of an image. It has complex structure, it is not byte matrix. Modification of first byte in it will most likely render it invalid. You better apply your modifications to image . And then save image as JPEG.