Question

我有一些限制，我不会指定要求我使用ImageMagick作为子进程。

我有多个基本的64个jpg文件字符串，我希望ImageMagick处理。具体来说，我希望ImageMagick将jpg文件加入到一起。如果我有2个常规jpg文件，那么从命令行我将使用以下格式。

node convert in_1.jpg in_2.jpg +append out.jpg

在js文件中我会使用

var spawn, magicCommands, imagic;
spawn = require('child_process').spawn;
magicCommands = ["in_1.jpg",
                 "in_2.jpg",
                 "+append",
                 "out.jpg"];
imagic = spawn("convert", magicCommands);

现在，如果我想使用 1 stdin缓冲区，则以下方法可以正常工作

    var arrow1JpgBase64, arrow2JpgBase64, arrowBuffer1, arrowBuffer2, magicCommands, imagic;

    spawn = require('child_process').spawn;
    exec = require('child_process').exec;

    arrow1JpgBase64 = "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";
    arrow2JpgBase64 = "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";
    arrowBuffer1 = new Buffer(arrow1JpgBase64, 'base64');
    arrowBuffer2 = new Buffer(arrow2JpgBase64, 'base64');
    magicCommands = ["jpg:",
                     "in_2.jpg",
                     "+append",
                     "out.jpg"];

    imagic = spawn("convert", magicCommands);
    imagic.stdin.write(arrowBuffer1);
    imagic.stdin.end();

    imagic.on('exit', function (code) {
        if (code === 0) {
            exec("open out.jpg");
        } else {
            console.log("error code: " + code);
        }
    }); // end of on exit

到目前为止一切顺利，但我想使用两个缓冲区，而不仅仅是 1 。因此，如果我将"in_2.jpg",行替换为"jpg:",，那么如何更改脚本的其余部分才能使其生效？

由于

Answer 1

Mark Setchell在评论中指出，使用ImageMagick的fd:协议将起作用。

var spawnOptions = {
      stdio: [
        0, // stdin,
        1, // stdout
        2, // stderr
        'pipe', // arrowBuffer1
        'pipe'  // arrowBuffer2
      ]
};
magic = spawn("convert", magicCommands, spawnOptions);

这会打开fd:3＆amp; fd:4用于管道。我对node.js系列没有失败，但除了pipe之外，通常还有一种方法可以传递资源。

代码

更新magickCommands变量以从新fd中读取，并直接写入新的pipes

magicCommands = ["fd:3",
                 "fd:4",
                 "+append",
                 "out.jpg"];

// ...
imagic.stdio[3].write(arrowBuffer1);
imagic.stdio[4].write(arrowBuffer2);
imagic.stdio[3].end();
imagic.stdio[4].end();

Answer 2

不确定这些＆＃34;限制＆＃34; 是什么，或者我们试图避免或解决的问题，但以下将多个文件合并为一个文件的技术可以帮助您：

# Make a red block
convert -size 50x50 xc:red multi.miff

# Make a green block, but APPEND INTO A SINGLE STREAM
convert -size 50x50 xc:lime miff:- >> multi.miff

# Make a blue block, but APPEND INTO A SINGLE STREAM
convert -size 50x50 xc:blue miff:- >> multi.miff

# Tell IM to convert and append multiple images in single stream 
convert multi.miff +append result.png

此外，如果您将上面的上一个命令更改为以下命令，IM会在完成后立即删除文件multi.miff - 即为您整理！

convert ephemeral:multi.miff +append result.png

将2个stdin参数传递给ImageMagick child_process

2 个答案: