Android's more reliable picture compression

First: Let's look at the mass compression method first:

Private Bitmap Compressimage (Bitmap image) {

Bytearrayoutputstream BAOs = new Bytearrayoutputstream ();

Image.compress (Bitmap.CompressFormat.JPEG, BAOs);//mass compression method, where 100 means no compression, the compressed data stored in the BAOs

int options = 100;

while (Baos.tobytearray (). length/1024>100) {//loops to determine if the picture is larger than 100kb after compression, greater than continue compression

Baos.reset ()//reset BAOs Clear BAOs

Image.compress (Bitmap.CompressFormat.JPEG, Options, BAOs)//Here compress the options% and store the compressed data in the BAOs

Options-= 10;//is reduced by 10 each time

}

Bytearrayinputstream ISBM = new Bytearrayinputstream (Baos.tobytearray ())//The compressed data BAOs stored in the Bytearrayinputstream

Bitmap Bitmap = Bitmapfactory.decodestream (ISBM, NULL, NULL);//To generate a picture of bytearrayinputstream data

return bitmap;

}

Second: The picture by the proportional size compression method (obtains the picture according to the path and compresses):

Private Bitmap getimage (String srcpath) {

Bitmapfactory.options newopts = new Bitmapfactory.options ();

Start reading into the picture and set options.injustdecodebounds back to True

Newopts.injustdecodebounds = true;

Bitmap Bitmap = Bitmapfactory.decodefile (srcpath,newopts);//This time return bm is empty

Newopts.injustdecodebounds = false;

int w = newopts.outwidth;

int h = newopts.outheight;

Now mainstream phones are more 800*480 resolution, so high and wide we set to

float hh = 800f;//Set height to 800f here

float ww = 480f;//set width to 480f here

Scaling ratio. Because it is a fixed scaling scale, only one of the data is high or wide to calculate

int be = 1;//be=1 means no scaling

if (W > H && w > ww) {//If the width is large zoom based on width fixed size

be = (int) (NEWOPTS.OUTWIDTH/WW);

else if (W < h && h > hh) {//if height is scaled according to width fixed size

be = (int) (NEWOPTS.OUTHEIGHT/HH);

}

if (be <= 0)

be = 1;

Newopts.insamplesize = be;//Set Scale

Re-read the picture, note that the options.injustdecodebounds has been set back to false at this time

Bitmap = Bitmapfactory.decodefile (Srcpath, newopts);

Return Compressimage (bitmap);//compress a good proportional size and then mass compress

}

Third: The picture by the proportional size compression method (according to bitmap picture compression):

Private Bitmap Comp (Bitmap image) {

Bytearrayoutputstream BAOs = new Bytearrayoutputstream ();

Image.compress (Bitmap.CompressFormat.JPEG, BAOs);

if (Baos.tobytearray (). length/1024>1024) {//Judge if the picture is greater than 1M, compress to avoid overflow when generating picture (Bitmapfactory.decodestream)

Baos.reset ()//reset BAOs Clear BAOs

Image.compress (Bitmap.CompressFormat.JPEG, BAOs), Compress 50%, store the compressed data in the BAOs

}

Bytearrayinputstream ISBM = new Bytearrayinputstream (Baos.tobytearray ());

Bitmapfactory.options newopts = new Bitmapfactory.options ();

Start reading into the picture and set options.injustdecodebounds back to True

Newopts.injustdecodebounds = true;

Bitmap Bitmap = Bitmapfactory.decodestream (ISBM, NULL, newopts);

Newopts.injustdecodebounds = false;

int w = newopts.outwidth;

int h = newopts.outheight;

Now mainstream phones are more 800*480 resolution, so high and wide we set to

float hh = 800f;//Set height to 800f here

float ww = 480f;//set width to 480f here

Scaling ratio. Because it is a fixed scaling scale, only one of the data is high or wide to calculate

int be = 1;//be=1 means no scaling

if (W > H && w > ww) {//If the width is large zoom based on width fixed size

be = (int) (NEWOPTS.OUTWIDTH/WW);

else if (W < h && h > hh) {//if height is scaled according to width fixed size

be = (int) (NEWOPTS.OUTHEIGHT/HH);

}

if (be <= 0)

be = 1;

Newopts.insamplesize = be;//Set Scale

Re-read the picture, note that the options.injustdecodebounds has been set back to false at this time

ISBM = new Bytearrayinputstream (Baos.tobytearray ());

Bitmap = Bitmapfactory.decodestream (ISBM, NULL, newopts);

Return Compressimage (bitmap);//compress a good proportional size and then mass compress

}