我正在使用此代码:
Bitmap itemImage = reduceImageAtFilePathFromGallery(imageName);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
itemImage.compress(Bitmap.CompressFormat.PNG, 100, stream);
imageAnswer = Image.getInstance(stream.toByteArray());
private Bitmap reduceImageAtFilePathFromGallery(String filePath) {
// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filePath, o);
// The new size we want to scale to
final int REQUIRED_SIZE = 256;
// Find the correct scale value. It should be the power of 2.
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
if (width_tmp < REQUIRED_SIZE && height_tmp < REQUIRED_SIZE)
break;
width_tmp /= 2;
height_tmp /= 2;
scale *= 2;
}
// Decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
Bitmap bitmap = BitmapFactory.decodeFile(filePath, o2);
return bitmap;
}
但是图像质量变差了。 然后,我也试过下面的代码:
Image imageAnswer = getAndResizeImage(imageName);
private Image getAndResizeImage(String imageFilename){
final File imageFile = new File(imageFilename);
if (imageFile.exists()) {
Bitmap b = null;
try {
File f = new File(imageFilename);
b = BitmapFactory.decodeFile(f.getAbsolutePath());
//calculate how many bytes our image consists of.
int bytes = getSizeInBytes(b);
ByteBuffer buffer = ByteBuffer.allocate(bytes); //Create a new buffer
b.copyPixelsToBuffer(buffer); //Move the byte data to the buffer
byte[] array = buffer.array(); //Get the underlying array containing the data.
Image image = Image.getInstance(array);
return image;
} catch (Exception e) {
e.printStackTrace();
return null;
}
return null;
}
并且它给出了这个错误:
09-09 15:08:58.368:W / S
ystem.err(1385):java.io.IOException:字节数组不是 认可的图像格式。 09-09 15:08:58.378:W / System.err(1385):at com.itextpdf.text.Image.getInstance(Image.java:442)09-09
在这行代码上:
Image image = Image.getInstance(array);
有什么方法可以使用iText在PDF上获得高质量的图像?
答案 0 :(得分:1)
使用JPEG压缩格式而非PNG
itemImage.compress(Bitmap.CompressFormat.JPEG, 100, stream);