我怎样才能通过一个.gif图像中每个像素循环？

问题描述

我需要到步骤通过.gif图像，并确定各像素的x和y坐标的RGB值。有人可以给我的，我怎么能做到这一点的概况？ （方法，其命名空间的使用，等等。）

I need to step through a .gif image and determine the RGB value of each pixel, x and y coordinates. Can someone give me an overview of how I can accomplish this? (methodology, which namespaces to use, etc.)

推荐答案

这是这两种方法一个完整的例子，使用LockBits（）和与getPixel（）。除了与LockBits的信任问题（）的东西就可以轻松搞定毛。所涉及的问题（步幅，格式，填充等）一个很好的解释位于。

This is a complete example with both methods, using LockBits() and GetPixel(). Besides the trust issues with LockBits() things can easily get hairy. A great explanation about the issues involved (Stride, Format, Padding and so on) is located here.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;

namespace BitmapReader
{
    class Program
    {
        static void Main(string[] args)
        {
            //Try a small pic to be able to compare output,
            //a big one to compare performance
            System.Drawing.Bitmap b = new
                System.Drawing.Bitmap(@"C:\Users\vinko\Pictures\Dibujo2.jpg");
            doSomethingWithBitmapSlow(b);
            doSomethingWithBitmapFast(b);
        }

        public static void doSomethingWithBitmapSlow(System.Drawing.Bitmap bmp)
        {
            for (int x = 0; x < bmp.Width; x++)
            {
                for (int y = 0; y < bmp.Height; y++)
                {
                    Color clr = bmp.GetPixel(x, y);
                    int red = clr.R;
                    int green = clr.G;
                    int blue = clr.B;
                    Console.WriteLine("Slow: " + red + " "
                                       + green + " " + blue);
                }
            }
        }

        public static void doSomethingWithBitmapFast(System.Drawing.Bitmap bmp)
        {
            Rectangle rect = new Rectangle(0, 0, bmp.Width, bmp.Height);

            System.Drawing.Imaging.BitmapData bmpData =
                bmp.LockBits(rect,
                    System.Drawing.Imaging.ImageLockMode.ReadOnly,
                    bmp.PixelFormat);

            IntPtr ptr = bmpData.Scan0;

            int bytes = bmpData.Stride * bmp.Height;
            byte[] rgbValues = new byte[bytes];

            System.Runtime.InteropServices.Marshal.Copy(ptr,
                           rgbValues, 0, bytes);

            byte red = 0;
            byte green = 0;
            byte blue = 0;

            for (int x = 0; x < bmp.Width; x++)
            {
                for (int y = 0; y < bmp.Height; y++)
                {
                    //See the link above for an explanation
                    //of this calculation
                    int position = (y * bmpData.Stride) + (x * Image.GetPixelFormatSize(bmpData.PixelFormat)/8);
                    blue = rgbValues[position];
                    green = rgbValues[position + 1];
                    red = rgbValues[position + 2];
                    Console.WriteLine("Fast: " + red + " "
                                       + green + " " + blue);
                }
            }
            bmp.UnlockBits(bmpData);
        }
    }
}

这篇关于我怎样才能通过一个.gif图像中每个像素循环？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！