server/helpers/image-utils.ts

   1 import { copy, readFile, remove, rename } from 'fs-extra'
   2 import Jimp, { read } from 'jimp'
   3 import { buildUUID, getLowercaseExtension } from '@shared/core-utils'
   4 import { convertWebPToJPG, processGIF } from './ffmpeg-utils'
   5 import { logger } from './logger'
   6
   7 function generateImageFilename (extension = '.jpg') {
   8   return buildUUID() + extension
   9 }
  10
  11 async function processImage (
  12   path: string,
  13   destination: string,
  14   newSize: { width: number, height: number },
  15   keepOriginal = false
  16 ) {
  17   const extension = getLowercaseExtension(path)
  18
  19   if (path === destination) {
  20     throw new Error('Jimp/FFmpeg needs an input path different that the output path.')
  21   }
  22
  23   logger.debug('Processing image %s to %s.', path, destination)
  24
  25   // Use FFmpeg to process GIF
  26   if (extension === '.gif') {
  27     await processGIF(path, destination, newSize)
  28   } else {
  29     await jimpProcessor(path, destination, newSize, extension)
  30   }
  31
  32   if (keepOriginal !== true) await remove(path)
  33 }
  34
  35 // ---------------------------------------------------------------------------
  36
  37 export {
  38   generateImageFilename,
  39   processImage
  40 }
  41
  42 // ---------------------------------------------------------------------------
  43
  44 async function jimpProcessor (path: string, destination: string, newSize: { width: number, height: number }, inputExt: string) {
  45   let sourceImage: Jimp
  46   const inputBuffer = await readFile(path)
  47
  48   try {
  49     sourceImage = await read(inputBuffer)
  50   } catch (err) {
  51     logger.debug('Cannot read %s with jimp. Try to convert the image using ffmpeg first.', path, { err })
  52
  53     const newName = path + '.jpg'
  54     await convertWebPToJPG(path, newName)
  55     await rename(newName, path)
  56
  57     sourceImage = await read(path)
  58   }
  59
  60   await remove(destination)
  61
  62   // Optimization if the source file has the appropriate size
  63   const outputExt = getLowercaseExtension(destination)
  64   if (skipProcessing({ sourceImage, newSize, imageBytes: inputBuffer.byteLength, inputExt, outputExt })) {
  65     return copy(path, destination)
  66   }
  67
  68   await autoResize({ sourceImage, newSize, destination })
  69 }
  70
  71 async function autoResize (options: {
  72   sourceImage: Jimp
  73   newSize: { width: number, height: number }
  74   destination: string
  75 }) {
  76   const { sourceImage, newSize, destination } = options
  77
  78   // Portrait mode targetting a landscape, apply some effect on the image
  79   const sourceIsPortrait = sourceImage.getWidth() < sourceImage.getHeight()
  80   const destIsPortraitOrSquare = newSize.width <= newSize.height
  81
  82   if (sourceIsPortrait && !destIsPortraitOrSquare) {
  83     const baseImage = sourceImage.cloneQuiet().cover(newSize.width, newSize.height)
  84                                               .color([ { apply: 'shade', params: [ 50 ] } ])
  85
  86     const topImage = sourceImage.cloneQuiet().contain(newSize.width, newSize.height)
  87
  88     return write(baseImage.blit(topImage, 0, 0), destination)
  89   }
  90
  91   return write(sourceImage.cover(newSize.width, newSize.height), destination)
  92 }
  93
  94 function write (image: Jimp, destination: string) {
  95   return image.quality(80).writeAsync(destination)
  96 }
  97
  98 function skipProcessing (options: {
  99   sourceImage: Jimp
 100   newSize: { width: number, height: number }
 101   imageBytes: number
 102   inputExt: string
 103   outputExt: string
 104 }) {
 105   const { sourceImage, newSize, imageBytes, inputExt, outputExt } = options
 106   const { width, height } = newSize
 107
 108   if (sourceImage.getWidth() > width || sourceImage.getHeight() > height) return false
 109   if (inputExt !== outputExt) return false
 110
 111   const kB = 1000
 112
 113   if (height >= 1000) return imageBytes <= 200 * kB
 114   if (height >= 500) return imageBytes <= 100 * kB
 115
 116   return imageBytes <= 15 * kB
 117 }