String picPath = "/mnt/sdcard/yepcolor/sina.png";
Bitmap bitmap = BitmapFactory.decodeFile(picPath);
I know the 'picPath' of the picture.Now, I want to get the picture's shooting time,and what should I do?Thanks.
As far as I know, png files doesn't contain such information. If you are reading jpeg files, however, you can use ExifInterface.
Related
I am working with a customizable database with pictures. Right now I am taking pictures as it is from the sdcard and encoding it in base64 String and then putting it in the database. but whenever I am trying decoding it and showing it in my view, I am getting Out of memory error. Can any one one tell me what is the best procedure to do it? Shall I change the size of the pictures before encoding it?
I want to re-size all of the pictures into 512*512.
Image to Base64 is very heavy operation in android. Consider saving the images on the external/internal memory and save the file path in the sqlite database.
You can convert your image to byte array then store values in sql by using BLOB type and vice versa.
As you mentioned you want to resize the images to 512*512, you can scale the image using below code,
Create bitmap from captured image and then use below line
Bitmap resizedBitmap = Bitmap.createScaledBitmap(myBitmap, 512, 512, false);
It will give you a smaller image, you can also consider compressing the image to reduce in size,
OutputStream imagefile = new FileOutputStream("/your/file/name.jpg");
// Write 'bitmap' to file using JPEG and 50% quality hint for JPEG:
bitmap.compress(CompressFormat.JPEG, 50, imagefile);
Now, you have two options,
Save the scaled and compressed image into a file and save the path of that file in db. (Better way)
Convert the scaled and compressed image to base64 string and save in db.
Althought base64 is , as many answers said, a heavy operation for android, if done properly, it should not be a problem.
There are many reasons a bitmap could be required to be saved to a DB , (photo of a invoice ticket, for example?), and this is the way i do it.
first, create a new , smaller bitmap like #Swapnil commented.
and second, correctly use the bitmap transformation methods, i've been using these (look below) two so far and haven't had any memory issue on many different devices.
link to my BitmapUtils transformation methods
It seems the answers I searched online (including stackoverflow.com) get the image file id through gallery selection.
I have created my own file explorer.
Then how to do that?
I can create my own small size image; but I think it would be faster if we can make use of an exisiting thumbnail; and if it does not exist, I would prefer to create a thumbnail that is saved for later use.
[Update:]
OK, thanks for advice. So I will not create a thumbnail in the device, to avoid to use too much space.
Then is is better to do two steps:
Step 1: look for an exisiting thumbnail for the image file if it exists.
Step 2: if no thumbnail exists, then create my own small size bitmap (not save the it).
Then how to do Step 1, if I do not use the Gallery intent?
[Update 2:]
I also want to get the thumbnail of a video file.
I can use MediaMetadataRetriever to get a frame at any point of time, and rescale the image to a thumbnail. But I find it is very slow: I have 4 video files in the folder, and I can sense the delay.
So I think the better way to retrieve an existing thumbnail.
If I only know the file path and file name, how can I get it?
I think this question is the same as my original one, just it has more sense to do so.
You shouldn't be using specific files for tumbnail, especially not creating tumbnails. What if the user has a lot of images and you store a tumbnail of each picture which gets viewed in your explorer. That would generated a whole lot of duplicated and unwanted data. The calculations from resizing the images each time overweighs the amount of data that would need to be stored.
I would suggest you have a default icon on images in the explorer and then resizing the images in a diffrent thread, replacing your default tumbnail as they are resized.
You could downsize the existing images on the fly:
BitmapFactory.Options opts = new BitmapFactory.Options();
opts.inJustDecodeBounds = true;
BitmapFactory.decodeFile(image_path, opts);
int width = opts.outWidth;
int height = opts.outHeight;
then
opts.inPreferredConfig = Bitmap.Config.ARGB_8888;
opts.inDither = true;
opts.inJustDecodeBounds = false;
opts.inSampleSize = (int)Math.pow(2.0,Math.floor(Math.log(scale_factor)/Math.log(2)));//for example double scale_factor=(double)width/desired_dimension;
and finally:
Bitmap bm = BitmapFactory.decodeFile(image_path,opts);
You could load in a separate thread ranges of existing files and update only those ones when needed.
You can use ThumbnailUtils. Look up the this utility method. Probably fits your need without much hassles. Creating duplicate downsized images is a bad design as that it will end up unnecessary data.
Bitmap resizedImage = ThumbnailUtils.extractThumbnail(rescaledImage, imagePixel, imagePixel);
I know it is possible to save bitmap to png or jpg
now i want to save bitmap to .tiff,anybody can help?
Android does not have native support for saving TIFF files.
You best bet would be to get the raw byte array, and then using either a Java or NDK library (like libtiff) to save it as a TIFF.
I believe this is is a repost from here:
Convert a bitmap image to an uncompressed tif image in Java
To answer the question, the above answer suggested the following using the Java Advanced Imaging (JAI) library:
TIFFImageWriterSpi spi = new TIFFImageWriterSpi();
ImageWriter writer = spi.createWriterInstance();
ImageWriteParam param = writer.getDefaultWriteParam();
param.setCompressionMode(ImageWriteParam.MODE_DISABLED);
ImageOutputStream ios = ImageIO.createImageOutputStream(new File("output.tif"));
writer.setOutput(ios);
writer.write(null, new IIOImage(bmp, null, null), param);
You always can save the Bitmap as .png and convert it to .tiff
Android hasn't support for tiff images. You should use some library for working with tiff. For example my: https://github.com/Beyka/Android-TiffBitmapFactory
I need a (really fast) way to check if a JPG file is in RGB format (or any other format that Android can show).
Actually, at this moment, I just know if a JPG file can be show when I try to convert it to Bitmap using BitmapFactory.
I think this should not be the fastest way. So I try to get it by using ExifInterface. Unfortunately, ExifInterface (from Android) does not have any tag that indicates that the jpg can be shown in Android (color space tag or something).
Then, I think I have 2 ways:
1) A fast way to get bitmap from jpg: any tip of how to do it?
2) Or try to read Exif tags by my self, but without adding any other lib to the project: I don't have any idea of how to do it!
Ok so I did some looking around and I may have a solution for you but it may require a little work. The link is a pure java library that I think you can use in your project or at least modify and include a few classes. I have not worked with this yet but it looks like it will work.
http://commons.apache.org/proper/commons-imaging
final ImageInfo imageInfo = Imaging.getImageInfo(File file);
if(imageInfo.getColorType() == ImageInfo.COLOR_TYPE_CMYK){
}
else {
}
My Problem is I am getting Image from Gallery & use BitmapFactory.decodeResource() for Convert the image into bitmap but the Problem is the Image is get in Emulator but not in Real Device, In Real Device the Bitmap value is getting null. following is my code for decode Gallery Image.
String Galleryimagepath="/mnt/sdcard/DCIM/.thumbnails/1308059312410.jpg";
bmpImage = BitmapFactory.decodeFile(Galleryimagepath);
drawable = new BitmapDrawable(bmpImage);
mRlayoutmainimage.setBackgroundDrawable(drawable);
Any Help would be appreciated.
Yashwanth is right, the path may be different between device and emulator, further, the path may different device to device as well. You'd be better off getting a content URI for the image you want and using MediaStore.Images.Thumbnails.getThumbnail() to get the bitmap you're looking for.
MediaStore.Images.Thumbnails
I think sd card path on real device is different. you might have to use something like
Environment.getExternalStorageState()
check the following link.
Find an external SD card location