RobotJS截取屏幕screen.capture踩坑

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RobotJS截取屏幕screen.capture踩坑

2023-02-20

2024-07-20

博客

nodejs

/

javascript

起因#

调用 robot.screen.capture() 或 robot.screen.capture(0,0,1920,1080)，返回的Bitmap对象是色彩格式是BGR色彩,这导致了如果未经处理就直接生成图像，色彩会产生错误，

处理方法#

只需将BGR色彩转换成RGB色彩即可。

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const robot = require('robotjs');
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const jimp = require("jimp");
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const swapRedAndBlueChannel = bmp => {
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    for (let i = 0; i < (bmp.width * bmp.height) * 4; i += 4) { // swap red and blue channel
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        [bmp.image[i], bmp.image[i + 2]] = [bmp.image[i + 2], bmp.image[i]]; // red channel;
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    }
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};
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const screenshot = robot.screen.capture();
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swapRedAndBlueChannel(screenshot);
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const screenJimp = new jimp({ data: screenshot.image, width: screenshot.width, height: screenshot.height });
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screenJimp.write('screenshot.png');

如果你有使用OpenCV，则可以使用“COLOR_BGR2RGB”函数直接转换

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const cv = require('@u4/opencv4nodejs');
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const robot = require('robotjs');
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const jimp = require("jimp");
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const screenshot = robot.screen.capture();
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const screenJimp = new jimp({ data: screenshot.image, width: screenshot.width, height: screenshot.height });
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screenJimp.getBuffer(jimp.MIME_PNG, function (err, buffer) {
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    if (err) {
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        return;
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    }
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    const screen = cv.imdecode(Buffer.from(buffer)).cvtColor(cv.COLOR_BGR2RGB);
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    console.log(screen)
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});