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画像をPDFに変換する方法は？

画像をPDFに変換する必要があるアプリケーションを開発しています。私は何かを試しましたが、問題は、その中の画像サイズPDFは非常に小さいです。これを修正する解決策が必要です。また、複数の画像を単一のPDF document。試したコードを投稿します。

    public void convertPDF(byte[] path)
{
 String FILE = "mnt/sdcard/FirstPdf.pdf";
    Document document=new Document();
    try {
        PdfWriter.getInstance(document, new FileOutputStream(FILE));
        document.open();

        try {
            image=Image.getInstance(path);
            document.add(new Paragraph("My Heading"));
            document.add(image);
            document.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    } catch (DocumentException e) {
        e.printStackTrace();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
}

ビットマップをバイト配列に変換するとき、画像を圧縮していますが、それが理由だと思います。画像を圧縮しないと、ビットマップをバイト配列に変換できません。

 ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bmp.compress(Bitmap.CompressFormat.PNG,100,stream);
        byte[] byteArray=stream.toByteArray();
        convertPDF(byteArray);

これに対する解決策はありますか？

[〜＃〜] updated [〜＃〜]

ここで、@ Burak Cakirが提案した回答を実装しました。しかし、今ではPDFで大きな画像を取得しています。よりよく理解するために、以下の画像を見つけてください。 enter image description here

実際の画像は enter image description here

androidandroid-imageandroid-bitmapandroid-pdf-api
11
Anish Kumar

iText pdfライブラリを使用することをお勧めします。 gradle依存関係は次のとおりです。

implementation 'com.itextpdf:itextg:5.5.10'

 Document document = new Document();

 String directoryPath = Android.os.Environment.getExternalStorageDirectory().toString();

 PdfWriter.getInstance(document, new FileOutputStream(directoryPath + "/example.pdf")); //  Change pdf's name.

 document.open();

 Image image = Image.getInstance(directoryPath + "/" + "example.jpg");  // Change image's name and extension.

 float scaler = ((document.getPageSize().getWidth() - document.leftMargin()
               - document.rightMargin() - 0) / image.getWidth()) * 100; // 0 means you have no indentation. If you have any, change it.
 image.scalePercent(scaler);
 image.setAlignment(Image.ALIGN_CENTER | Image.ALIGN_TOP); 

 document.add(image);
 document.close();
16
Burak Cakir

ここからソースコードをダウンロードします（ Convert Image to pdf in Android programmatically ）

MainActivity.Java:

package com.deepshikha.convertbitmap;

import Android.Manifest;
import Android.app.ProgressDialog;
import Android.content.Context;
import Android.content.Intent;
import Android.content.pm.PackageManager;
import Android.database.Cursor;
import Android.graphics.Bitmap;
import Android.graphics.BitmapFactory;
import Android.graphics.Canvas;
import Android.graphics.Color;
import Android.graphics.Paint;
import Android.graphics.pdf.PdfDocument;
import Android.net.Uri;
import Android.provider.MediaStore;
import Android.support.v4.app.ActivityCompat;
import Android.support.v4.content.ContextCompat;
import Android.support.v7.app.AppCompatActivity;
import Android.os.Bundle;
import Android.util.DisplayMetrics;
import Android.util.Log;
import Android.view.Display;
import Android.view.View;
import Android.view.WindowManager;
import Android.widget.Button;
import Android.widget.ImageView;
import Android.widget.Toast;

import Java.io.File;
import Java.io.FileOutputStream;
import Java.io.IOException;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    public static final int GALLERY_PICTURE = 1;
    Button btn_select, btn_convert;
    ImageView iv_image;
    boolean boolean_permission;
    boolean boolean_save;
    Bitmap bitmap;
    public static final int REQUEST_PERMISSIONS = 1;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();
        listener();
        fn_permission();
    }

    private void init() {
        btn_select = (Button) findViewById(R.id.btn_select);
        btn_convert = (Button) findViewById(R.id.btn_convert);
        iv_image = (ImageView) findViewById(R.id.iv_image);
    }

    private void listener() {
        btn_select.setOnClickListener(this);
        btn_convert.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.btn_select:
                Intent intent = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                startActivityForResult(intent, GALLERY_PICTURE);
                break;

            case R.id.btn_convert:
                if (boolean_save){

                    Intent intent1=new Intent(getApplicationContext(),PDFViewActivity.class);
                    startActivity(intent1);

                }else {
                    createPdf();
                }
                break;


        }
    }

    private void createPdf(){
        WindowManager wm = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
        Display display = wm.getDefaultDisplay();
        DisplayMetrics displaymetrics = new DisplayMetrics();
        this.getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
        float hight = displaymetrics.heightPixels ;
        float width = displaymetrics.widthPixels ;

        int convertHighet = (int) hight, convertWidth = (int) width;

//        Resources mResources = getResources();
//        Bitmap bitmap = BitmapFactory.decodeResource(mResources, R.drawable.screenshot);

        PdfDocument document = new PdfDocument();
        PdfDocument.PageInfo pageInfo = new PdfDocument.PageInfo.Builder(bitmap.getWidth(), bitmap.getHeight(), 1).create();
        PdfDocument.Page page = document.startPage(pageInfo);

        Canvas canvas = page.getCanvas();


        Paint paint = new Paint();
        Paint.setColor(Color.parseColor("#ffffff"));
        canvas.drawPaint(Paint);



        bitmap = Bitmap.createScaledBitmap(bitmap, bitmap.getWidth(), bitmap.getHeight(), true);

        Paint.setColor(Color.BLUE);
        canvas.drawBitmap(bitmap, 0, 0 , null);
        document.finishPage(page);


        // write the document content
        String targetPdf = "/sdcard/test.pdf";
        File filePath = new File(targetPdf);
        try {
            document.writeTo(new FileOutputStream(filePath));
            btn_convert.setText("Check PDF");
            boolean_save=true;
        } catch (IOException e) {
            e.printStackTrace();
            Toast.makeText(this, "Something wrong: " + e.toString(), Toast.LENGTH_LONG).show();
        }

        // close the document
        document.close();
    }



    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == GALLERY_PICTURE && resultCode == RESULT_OK) {

            if (resultCode == RESULT_OK) {
                Uri selectedImage = data.getData();
                String[] filePathColumn = {MediaStore.Images.Media.DATA};

                Cursor cursor = getContentResolver().query(
                        selectedImage, filePathColumn, null, null, null);
                cursor.moveToFirst();

                int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
                String filePath = cursor.getString(columnIndex);
                cursor.close();


                bitmap = BitmapFactory.decodeFile(filePath);
                iv_image.setImageBitmap(bitmap);


                btn_convert.setClickable(true);
            }
        }
    }

    private void fn_permission() {
        if ((ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)||
                (ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)) {

            if ((ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Android.Manifest.permission.READ_EXTERNAL_STORAGE))) {
            } else {
                ActivityCompat.requestPermissions(MainActivity.this, new String[]{Android.Manifest.permission.READ_EXTERNAL_STORAGE},
                        REQUEST_PERMISSIONS);

            }

            if ((ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE))) {
            } else {
                ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                        REQUEST_PERMISSIONS);

            }
        } else {
            boolean_permission = true;


        }
    }
    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == REQUEST_PERMISSIONS) {

            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                boolean_permission = true;


            } else {
                Toast.makeText(getApplicationContext(), "Please allow the permission", Toast.LENGTH_LONG).show();

            }
        }
    }


}

ありがとう！

9
Deepshikha Puri

JPGをPDFに変換するには、19以上のSDK（KitKat 4.4）をターゲットにし、GoogleのPdfDocument API（ https://developer.Android.com/reference/ Android/graphics/pdf/PdfDocument ）、以下のKotlinに示すとおり：

    // Load JPG file into bitmap
    val f: File = myJPGFile
    val bitmap: Bitmap  = BitmapFactory.decodeFile(f.absolutePath)

    // Create a PdfDocument with a page of the same size as the image
    val document: PdfDocument = PdfDocument()
    val pageInfo: PdfDocument.PageInfo  = PdfDocument.PageInfo.Builder(bitmap.width, bitmap.height, 1).create()
    val page: PdfDocument.Page  = document.startPage(pageInfo)

    // Draw the bitmap onto the page
    val canvas: Canvas = page.canvas
    canvas.drawBitmap(bitmap, 0f, 0f, null)
    document.finishPage(page)

    // Write the PDF file to a file
    val directoryPath: String  = Android.os.Environment.getExternalStorageDirectory().toString()
    document.writeTo( FileOutputStream(directoryPath + "/example.pdf"))
    document.close()
0
Anthony.