问题描述
我正在尝试使用 nodejs 和 JIMP 在简单的 jpg 或 png 上写一些文本,但我在使其工作时遇到问题。 图片来自电报机器人,它与另一张带有画布的图片合并,然后我必须在上面写一些简单的文字。
这是我的代码:
const Jimp = require("jimp");
var imageCaption = 'WRITE THIS ON PICTURE';
var loadedImage;
const image = await Jimp.read(finalCanvas)
.then(function (image) {
loadedImage = image;
return Jimp.loadFont(Jimp.FONT_SANS_16_BLACK);
})
.then(function (font) {
loadedImage.print(font,10,imageCaption)
.write(finalCanvas);
})
.catch(function (err) {
console.error(err);
});
我不断收到有关找不到匹配的构造函数重载的错误消息。 让 JIMP 读取我的本地文件也有问题。
我得到的完整错误:
Error: No matching constructor overloading was found. Please see the docs for how to call the Jimp constructor.
at Jimp.throwError (/home/smp0/ifsbadge/node_modules/@jimp/utils/dist/index.js:33:13)
at new Jimp (/home/smp0/ifsbadge/node_modules/@jimp/core/dist/index.js:412:85)
at _construct (/home/smp0/ifsbadge/node_modules/@babel/runtime/helpers/construct.js:19:21)
at /home/smp0/ifsbadge/node_modules/@jimp/core/dist/index.js:926:32
at new Promise (<anonymous>)
at Function.Jimp.read (/home/smp0/ifsbadge/node_modules/@jimp/core/dist/index.js:925:10)
at TelegramBot.<anonymous> (/home/smp0/ifsbadge/index.js:51:32)
at processticksAndRejections (internal/process/task_queues.js:93:5) {
methodName: 'constructor'
}
完整的上下文:
var needle = require('needle');
const Telegram = require('node-telegram-bot-api')
const { createCanvas,loadImage,ImageData } = require('canvas')
var Jimp = require("jimp");
var fs = require('fs');
const factions = {}
token="1234:BLABLA"
const bot = new Telegram(token,{ polling: true })
bot.on('message',async (msg) => {
if (msg.photo) {
if (factions[msg.chat.id]) {
console.log(`Generating badge for ${msg.from.first_name} (${msg.from.username})...`)
bot.sendChatAction(msg.chat.id,'upload_photo').catch(console.error)
const pictureCanvas = createCanvas(559,772)
const pictureCtx = pictureCanvas.getContext('2d')
const { file_path } = await bot.getFile(msg.photo[msg.photo.length - 1].file_id)
const picture = await loadImage(`https://api.telegram.org/file/bot${token}/${file_path}`)
// PICTURE CALculaTIONS
pheight = picture.height
pwidth = picture.width
aspectratiow = (pwidth/pheight)
aspectratioh = (pheight/pwidth)
oheight = pheight*aspectratioh
owidth = (pwidth) / (pwidth/559)
newheight = 559*pheight/pwidth
var scale = Math.min(559/pwidth,772/pheight);
var posx = (559 / 2) - (559 / 2) * scale;
var posy = (772 / 2) - (pheight / 2) * scale;
// END OF CALculaTIONS
// MERGING TWO PICTURES
pictureCtx.drawImage(picture,posy,559,newheight)
const finalCanvas = createCanvas(559,772)
const finalCtx = finalCanvas.getContext('2d')
const frame = await loadImage(`./frames/${factions[msg.chat.id]}.png`)
finalCtx.drawImage(pictureCanvas,772)
finalCtx.drawImage(frame,772)
factions[msg.chat.id] = null
// END OF MERGING PICTURES
//APPLYING TEXT ON PICTURE
const Jimp = require("jimp");
var imageCaption = 'WRITE THIS ON PICTURE';
var loadedImage;
const image = await Jimp.read(finalCanvas)
.then(function (image) {
loadedImage = image;
return Jimp.loadFont(Jimp.FONT_SANS_16_BLACK);
})
.then(function (font) {
loadedImage.print(font,imageCaption)
.write(finalCanvas);
})
.catch(function (err) {
console.error(err);
});
//END OF APPLYING TEXT ON PICTURE
bot.sendPhoto(msg.chat.id,finalCanvas.toBuffer('image/jpeg',{ quality: 1 }))
} else {
bot.sendMessage(msg.chat.id,'Write /enl1 /enl2 /enl3 o /res1 /res2 /res3 o /xf1 /xf2 !').catch(console.log)
}
}
})
bot.onText(/\/start/,async (msg) => {
bot.sendMessage(msg.chat.id,"Welcome! Select your badge Write /enl1 /enl2 /enl3 o /res1 /res2 /res3 o /xf1 /xf2 !").catch(console.log)
})
bot.onText(/\/(enl1|enl2|enl3|res1|res2|res3|xf1|xf2)/,async (msg,match) => {
factions[msg.chat.id] = match[1]
bot.sendMessage(msg.chat.id,'Good! Now send me your picture').catch(console.log)
})
github 上的源代码:https://github.com/pedrofracassi/badgemaker 和 https://github.com/FerdinandoLM/IngressFSBadgeMaker
解决方法
据我所知,finalCanvas
是 Canvas
的一个实例。我不认为 Jimp
会采用 Canvas
的实例,但 Canvas#toBuffer()
可能是您想要的东西,因为 Jimp
会采用缓冲区:Jimp.read(finalCanvas.toBuffer())
http.get
和 response.pipe(writeStream)
都是异步的。在您尝试 Jimp.read
时,该文件尚未在文件系统中或尚未完全写入磁盘。
要在写入文件后执行此操作,请收听 finish
事件。
file.on('finish',async () => {
await Jump.read(...);
});