我正在开发一个将位图作为 jpeg 图像保存到外部存储的 Android 应用程序。JPEG 有时会损坏（见下图）。我已经意识到只有在调用 saveExif() 时才会发生损坏（最终）。如果我注释掉 saveExif()，则永远不会发生损坏。这意味着它是由与 EXIF 相关的东西引起的，而不是由压缩过程引起的。我已经使用软件（Bad Peggy）分析了 jpeg，该软件检测到图像由于数据段过早结束而损坏。
知道如何解决吗？
这是我最初保存图像的方式：
lateinit var uri: Uri
val imageOutStream: OutputStream
val contentResolver = context.contentResolver
val mimeType = "image/jpeg"
val mediaContentUri = MediaStore.Images.Media.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)
val values = ContentValues().apply {
put(MediaStore.Images.Media.DISPLAY_NAME, fileName)
put(MediaStore.Images.Media.MIME_TYPE, mimeType)
put(MediaStore.Images.Media.RELATIVE_PATH, directory)
}
contentResolver.run {
uri = context.contentResolver.insert(mediaContentUri, values)
?: return
imageOutStream = openOutputStream(uri) ?: return
}
try {
imageOutStream.use { bitmap.compress(Bitmap.CompressFormat.JPEG, photoCompression, it) }
} catch (e: java.lang.Exception) {
e.printStackTrace()
} finally {
imageOutStream.close()
}
try {
context.contentResolver.openInputStream(uri).use {
val exif = ExifInterface(context.contentResolver.openFileDescriptor(uri, "rw")!!.fileDescriptor)
saveExif(exif, context) //method ads exif metadata to image
}
}catch (e: java.lang.Exception){
}
这是我在存储 JPEG 后添加 Exif 元数据的方式：
private fun saveExif(exif: ExifInterface, context: Context){
if (referenceWithCaptionExif != "" && notesExif != "") {
exif.setAttribute(ExifInterface.TAG_USER_COMMENT, "$referenceWithCaptionExif | $notesExif")
} else {
exif.setAttribute(ExifInterface.TAG_USER_COMMENT, "$referenceWithCaptionExif$notesExif")
}
if (companyExif != "") {
exif.setAttribute(ExifInterface.TAG_CAMERA_OWNER_NAME, companyExif)
val yearForExif = SimpleDateFormat("yyyy",
Locale.getDefault()).format(Date())
exif.setAttribute(ExifInterface.TAG_COPYRIGHT, "Copyright (c) $companyExif $yearForExif")
}
if (projectExif != "") {
exif.setAttribute(ExifInterface.TAG_IMAGE_DESCRIPTION, projectExif)
}
exif.setAttribute(ExifInterface.TAG_MAKER_NOTE, "Project[$projectExif] Company[$companyExif] " +
"Notes[$notesExif] Reference[$referenceExif] ReferenceType[$referenceTypeExif] Coordinates[$coordinatesExif] " +
"CoordinateSystem[$coordinateSystemExif] Accuracy[$accuracyExif] Altitude[$altitudeExif] " +
"Date[$dateTimeExif] Address[$addressExif]")
exif.setAttribute(ExifInterface.TAG_ARTIST, "${android.os.Build.MANUFACTURER} ${android.os.Build.MODEL}")
exif.setAttribute(ExifInterface.TAG_SOFTWARE, context.resources.getString(R.string.app_name))
exif.setAttribute(ExifInterface.TAG_MAKE, (android.os.Build.MANUFACTURER).toString())
exif.setAttribute(ExifInterface.TAG_MODEL, (android.os.Build.MODEL).toString())
exif.setAttribute(ExifInterface.TAG_COMPRESSION, 7.toString())
exif.setAttribute(ExifInterface.TAG_IMAGE_WIDTH, "${bitmapToProcess.width} px")
exif.setAttribute(ExifInterface.TAG_IMAGE_LENGTH, "${bitmapToProcess.height} px")
exif.setAttribute(ExifInterface.TAG_PIXEL_X_DIMENSION, "${bitmapToProcess.width} px")
exif.setAttribute(ExifInterface.TAG_PIXEL_Y_DIMENSION, "${bitmapToProcess.height} px")
exif.setAttribute(ExifInterface.TAG_GPS_ALTITUDE, altitudeExif)
exif.setAttribute(ExifInterface.TAG_GPS_ALTITUDE_REF, 0.toString())
exif.setAltitude(altitudeMetricExif)
exif.setLatLong(latitudeWGS84Exif, longitudeWGS84Exif)
exif.setAttribute(ExifInterface.TAG_GPS_TIMESTAMP, timeGPSExif)
exif.setAttribute(ExifInterface.TAG_GPS_DATESTAMP, dateGPSExif)
exif.setAttribute(ExifInterface.TAG_GPS_PROCESSING_METHOD, "GPS")
exif.setAttribute(ExifInterface.TAG_DATETIME, dateTimeOriginalExif)
exif.setAttribute(ExifInterface.TAG_DATETIME_ORIGINAL, dateTimeOriginalExif)
exif.setAttribute(ExifInterface.TAG_DATETIME_DIGITIZED, dateTimeOriginalExif)
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.N){
exif.setAttribute(ExifInterface.TAG_OFFSET_TIME_DIGITIZED, SimpleDateFormat("XXX", Locale.getDefault()).format(Date()))
exif.setAttribute(ExifInterface.TAG_OFFSET_TIME_ORIGINAL, SimpleDateFormat("XXX", Locale.getDefault()).format(Date()))
exif.setAttribute(ExifInterface.TAG_OFFSET_TIME, SimpleDateFormat("XXX", Locale.getDefault()).format(Date()))
}
exif.saveAttributes()
}
