function keepExif () {
  this.options.keepMetadata |= 0b00001;
  return this;
}
Keep all EXIF metadata from the input image in the output image.

EXIF metadata is unsupported for TIFF output.

@since 0.33.0

@example
const outputWithExif = await sharp(inputWithExif)
  .keepExif()
  .toBuffer();

@returns {Sharp}