不存在从"Magick::Color"到"MagickCore::Quantum"的合适转换功能

no suitable conversion function from "Magick::Color" to "MagickCore::Quantum" exists

本文关键字：转换 功能 Quantum Magick Color 不存在 MagickCore      更新时间：2023-10-16

我已经知道为什么它会给出错误代码。问题是，我今天开始使用库本身，并遵循我发现的教程。

我安装了该库的"ImageMagick-7.09-1-Q16-x64-dll"版本，并试图找到出现该错误的最短代码，即：

#include <Magick++.h>
int main(){
Magick::Quantum result = Magick::Color("black");
}

给定教程(以下教程(，一个从Magick:：Color转换为Magic:：Quantum的方法应该存在

// Example of using an image pixel cache
Image my_image("640x480", "white"); // we'll use the 'my_image' object in this example
my_image.modifyImage(); // Ensure that there is only one reference to
// underlying image; if this is not done, then the
// image pixels *may* remain unmodified. [???]
Pixels my_pixel_cache(my_image); // allocate an image pixel cache associated with my_image
Quantum* pixels; // 'pixels' is a pointer to a Quantum array
// define the view area that will be accessed via the image pixel cache
int start_x = 10, start_y = 20, size_x = 200, size_y = 100;
// return a pointer to the pixels of the defined pixel cache
pixels = my_pixel_cache.get(start_x, start_y, size_x, size_y);
// set the color of the first pixel from the pixel cache to black (x=10, y=20 on my_image)
*pixels = Color("black");
// set to green the pixel 200 from the pixel cache:
// this pixel is located at x=0, y=1 in the pixel cache (x=10, y=21 on my_image)
*(pixels+200) = Color("green");
// now that the operations on my_pixel_cache have been finalized
// ensure that the pixel cache is transferred back to my_image
my_pixel_cache.sync();

这在的以下行给出了错误(不存在从"Magick:：Color"到"MagickCore:：Quantum"的合适转换函数(

*pixels = Color("black");
*(pixels+200) = Color("green");

我认为您混淆了数据类型和结构。pixels表示Quantum部件的连续列表。

假设我们使用的是RGB颜色空间。您需要设置每个颜色部分。

Color black("black");
*(pixels + 0) = black.quantumRed();
*(pixels + 1) = black.quantumGreen();
*(pixels + 2) = black.quantumBlue();

要设置第200个像素，需要将偏移量乘以每个像素的部分数。

Color green("green");
int offset = 199 * 3; // First pixel starts at 0, and 3 parts (Red, Green, Blue)
*(pixels + offset + 0) = green.quantumRed();
*(pixels + offset + 1) = green.quantumGreen();
*(pixels + offset + 2) = green.quantumBlue();
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