在C ++中获取像素颜色 [英] Getting pixel color in C++

问题描述

我想得到像素在屏幕上不同x，y坐标的RGB值。
我将如何在C ++中这样做？

我试图创建我自己的高斯模糊效果。

这将是在Windows 7中。

编辑 b
$ b

需要包含哪些库才能运行？

我要做什么：

  #include< iostream> 
 
 using namespace std; 
 
 int main（）{
 
 HDC dc = GetDC（NULL）; 
 COLORREF color = GetPixel（dc，0，0）; 
 ReleaseDC（NULL，dc）; 
 
 cout<<颜色; 
 
} 
  

解决方案

在上一篇文章中，您希望 GetPixel 函数从Win32 API。

GetPixel位于gdi32.dll内部，所以如果你有一个合适的环境设置，你应该能够包括windows.h

如果你有一个最小的环境设置，无论什么原因，你也可以直接使用gdi32.dll上的LoadLibrary。

GetPixel的第一个参数是设备上下文的句柄，可以通过调用GetDC函数（也可通过< windows。

从dll加载GetPixel并打印出光标所在像素的颜色的一个基本示例如下。

 ＃include< windows.h> 
＃include< stdio.h> 
 
 int main（int argc，char ** argv）
 {
 FARPROC pGetPixel; 
 
 HINSTANCE _hGDI = LoadLibrary（gdi32.dll）; 
 if（_hGDI）
 {
 pGetPixel = GetProcAddress（_hGDI，GetPixel）; 
 HDC _hdc = GetDC（NULL）; 
 if（_hdc）
 {
 POINT _cursor; 
 GetCursorPos（& _cursor）; 
 COLORREF _color =（* pGetPixel）（_hdc，_cursor.x，_cursor.y）; 
 int _red = GetRValue（_color）; 
 int _green = GetGValue（_color）; 
 int _blue = GetBValue（_color）; 
 
 printf（Red：0x％02x\\\
，_red）; 
 printf（Green：0x％02x\\\
，_green）; 
 printf（Blue：0x％02x\\\
，_blue）; 
} 
 FreeLibrary（_hGDI）; 
 
 return 0; 
} 
  

I would like to get the RGB values of a pixel at different x, y coordinates on the screen. How would I go about this in C++?

I'm trying to create my own gaussian blur effect.

This would be in Windows 7.

Edit

What libraries need to be included for this to run?

What I have going:

#include <iostream>

using namespace std ;

int main(){

    HDC dc = GetDC(NULL);
    COLORREF color = GetPixel(dc, 0, 0);
    ReleaseDC(NULL, dc);

    cout << color; 

}

解决方案

As mentioned in a previous post, you want the GetPixel function from the Win32 API.

GetPixel sits inside gdi32.dll, so if you have a proper environment setup, you should be able to include windows.h(which includes wingdi.h) and you should be golden.

If you have a minimal environment setup for whatever reason, you could also use LoadLibrary on gdi32.dll directly.

The first parameter to GetPixel is a handle to the device context, which can be retrieved by calling the GetDC function(which is also available via <windows.h>).

A basic example that loads GetPixel from the dll and prints out the color of the pixel wherever your cursor is is as follows.

#include<windows.h>
#include<stdio.h>

int main(int argc, char** argv)
{
    FARPROC pGetPixel;

    HINSTANCE _hGDI = LoadLibrary("gdi32.dll");
    if(_hGDI)
    {
        pGetPixel = GetProcAddress(_hGDI, "GetPixel");
        HDC _hdc = GetDC(NULL);
    if(_hdc)
    {
        POINT _cursor;
        GetCursorPos(&_cursor);
        COLORREF _color = (*pGetPixel) (_hdc, _cursor.x, _cursor.y);
        int _red = GetRValue(_color);
        int _green = GetGValue(_color);
        int _blue = GetBValue(_color);

        printf("Red: 0x%02x\n", _red);
        printf("Green: 0x%02x\n", _green);
        printf("Blue: 0x%02x\n", _blue);
    }
    FreeLibrary(_hGDI);

    return 0;
}

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