Good day ,I am generating certificates and for this I have a template where I must write user data, for the moment I am creating the certificates in pdf format, but the ideal would be to use images or convert those pdf to image since it is easier for the user to handle images, I have not found any library capable of writing in images that works correctly.
At the moment I am trying to use Image. https://pub.dev/packages/image.
I have the following code, but it fails to add a text fragment in the image.
imagecert = await ManagerDB().getcertificate(certificatetemplate); //imagecert is uint8list
if (imagecert != null) {
mg.Image ima = mg.Image.fromBytes(300, 200, List.from(imagecert)); Image works with list<int>
mg.Image imag = mg.drawString(ima, mg.arial_14, 0, 0, 'Hello World'); //here the code does not work
List<int> data = mg.encodePng(imag);
Uint8List bytes = Uint8List.fromList(data);
setState(() {});
return bytes;
} else {
print("Enlace no encontrado");
}
I don't know if there is a simpler solution to write text in an image. It is required to store those images.
Thank you
you can put image inside widget and add to that widget text
and converted to image using globalKey (don't forget to pass globalKey to key of that sepecific widget )
Future<Uint8List> _convertWidgetToImage(GlobalKey globalKey) async {
RenderRepaintBoundary boundary =
globalKey.currentContext!.findRenderObject() as RenderRepaintBoundary;
ui.Image image = await boundary.toImage();
ByteData byteData =
(await (image.toByteData(format: ui.ImageByteFormat.png)))!;
Uint8List pngBytes = byteData.buffer.asUint8List();
return pngBytes;
}
After reading an image with the ImageDescriptor API and resizing it by instantiating a codec I am trying to write the resized version in the application directory.
I saw that the when converting the frame into byte data I have a format which is rawUnmodified which I assumed would write the resized image in the same format as the original image. But when I tried to load the resized image I get an image format exception.
Example code:
//read the original image and obtain the image descriptor
var imageData = await file.readAsBytes();
final ImmutableBuffer buffer = await ImmutableBuffer.fromUint8List(imageData);
final imDescr = await ImageDescriptor.encoded(buffer);
//resize the image, get the first frame and convert it to bytes
Codec codec = await imDescr.instantiateCodec(targetWidth: 100, targetHeight: 100);
FrameInfo frameInfo = await codec.getNextFrame();
var bytes = await frameInfo.image.toByteData(
format: ImageByteFormat.rawUnmodified,
//note when using the png format it works, but I would like to have it in the original image format(in this case its jpg)
);
//write the resized image
Directory appDir = await getApplicationDocumentsDirectory();
var path = appDir.path;
var file = File('$path/test1.jpg');
await file.writeAsBytes(bytes.buffer.asUint8List(bytes.offsetInBytes, bytes.lengthInBytes));
In the ImageByteFormat api it says: rawUnmodified -> Unencoded bytes, in the image's existing format. For example, a grayscale image may use a single 8-bit channel for each pixel.
But when I try to show this image the format is wrong. Anybody have an idea how to fix this?
Why use image ImageDescriptor, You can do it easily by image package
File resizeImage(File imageFile, String imageFormat, int targetWidth, int targetHeight) {
im.Image tempImage = im.decodeImage(imageFile.readAsBytesSync());
tempImage = im.bakeOrientation(tempImage);
tempImage = im.copyResize(tempImage, width: targetWidth, height: targetHeight);
File newImage;
if (imageFormat == 'jpg') {
newImage = File('newpath/test.jpg');
newImage.writeAsBytesSync(im.encodeJpg(tempImage));
return newImage;
} else if (imageFormat == 'png') {
newImage = File('newpath/test.png');
newImage.writeAsBytesSync(im.encodePng(tempImage));
return newImage;
} else {
throw ('Unknown Image Format');
}
}
Stuck in the basics. I have some syntax issues setting up the Image Path.
When i try to create an Image and give it the image path, it always throws some some exception about the path. I have commented out some of the path combination I have already tryed. Can you please tell me what I am doing wrong? Thank you.
package jopofx;
public JoPoCTRL(JoPoFX gui){
this.gui = gui;
}
public void updateImages(){
Image img = null;
try{
//img = new Image("C:\\Users\\ ... //FullPath ... \\JoPoFX\\src\\jopofx\\myimage.png");
img = new Image("\\JoPoFX\\src\\jopofx\\myimage.png");
//img = new Image("\\src\\jopofx\\myimage.png");
//img = new Image("\\myimage.png");
}catch(Exception e){
System.out.println("error while creating image");
e.printStackTrace();
}
try{
gui.setImgV(img);
}catch(Exception e){
System.out.println("error while setting up the image");
}
}
This is what prints out:
error while creating image
java.lang.IllegalArgumentException: Invalid URL: Invalid URL or resource not found
at javafx.scene.image.Image.validateUrl(Image.java:990)
at javafx.scene.image.Image.(Image.java:538)
On Windows platform, for an image placed inside src/jopofx :
img = new Image("\\jopofx\\myimage.png");
or
img = new Image("/jopofx/myimage.png");
Then you can create an ImageView using:
ImageView imageView = new ImageView(img);
Further, you can also directly initialize an ImageView without initializing an Image by:
ImageView imageView = new ImageView("/jopofx/myimage.png");
Also, make sure you are using the import javafx.scene.image.Image;
I found a working example from a blog short after I posted my question.
Hopefully this example will be helpful to someone:
InputStream stream = getClass().getResourceAsStream("images/"+imageName+".jpg");
//"images/" is the a local directory where all my images are located
Image newImage = new Image(stream);
imgV.setImage(newImage);
I have built my application using scenebuilder for javafx. I have a form where a person has to upload an image. I used this code
public void photoChooser(ActionEvent evt) {
System.out.println("photoChooser method is called");
try{
FileChooser fileChooser= new FileChooser();
fileChooser.setTitle("Choose a file");
File file = fileChooser.showOpenDialog(stagehere);
if(file != null){
System.out.println(file);
String img = file.toString();
//Image image = new ImageIcon(img);
try{
// image= new Image();
Image image = new Image(img);
} catch (Exception e) {System.out.println("Can't upload image " + e);}
//employeeImage.setImage(image);
try{
// employeeImage.setImage(image);
} catch(Exception e){System.out.println("Can't set the image" + e);}
employeeImage.setFitWidth(150);
employeeImage.setFitHeight(150);
}
And I got this error
photoChooser method is called
A:\images\fb\status\asd.jpg
Can't upload image java.lang.IllegalArgumentException: Invalid URL: unknown protocol: a
The constructor of Image expects an URL and not a file path. Therefore if there is a ":" in the string, everything up to that point is interpreted as the protocol (normally something like http, file or ftp).
You have to change the line
String img = file.toString();
to
String img = file.toURI().toURL().toExternalForm();
This gets the URL from the file before converting to string. I converted to URI first since File.toURL is deprecated and that's the suggested "workaround".
I'm new to working with PdfBox and I'm having a small issue when displaying images. I'm able to import the image, which is sized at 800*900 pixels, and looks fine when viewed in an existing pdf at 100%. However when the resulting PDF is generated using the below code, the image becomes blurry, and the image extends beyond the boundaries of the A4 page.
Is there a different way of sizing/saving images so that they display correctly in pdfbox?
public class PDFtest {
/**
* #param args the command line arguments
*/
public static void main(String[] args) throws IOException, COSVisitorException {
// TODO code application logic here
// Create a document and add a page to it
PDDocument document = new PDDocument();
PDPage page = new PDPage(PDPage.PAGE_SIZE_A4);
document.addPage(page);
// Create a new font object selecting one of the PDF base fonts
PDFont font = PDType1Font.HELVETICA_BOLD;
InputStream in = new FileInputStream(new File("img.jpg"));
PDJpeg img = new PDJpeg(document, in);
// Start a new content stream which will "hold" the to be created content
PDPageContentStream contentStream = new PDPageContentStream(document, page);
// Define a text content stream using the selected font, moving the cursor and drawing the text "Hello World"
contentStream.drawImage(img, 10, 700);
contentStream.beginText();
contentStream.setFont(font, 12);
contentStream.moveTextPositionByAmount(10, 650);
contentStream.drawString("Hello World");
contentStream.endText();
// Make sure that the content stream is closed:
contentStream.close();
// Save the results and ensure that the document is properly closed:
document.save("Hello World.pdf");
document.close();
}
I'd like to point out that as of 2.0 the contentStream.drawXObject function call in Victor's answer is deprecated. If you want to specify a width and height you should use contentStream.drawImage(image, x, y, width, height)
I had the same problem asked in this question, but the given answer is not right.
After some research I found a solution.
Instead of using the function drawImage use the function drawXObject
contentStream.drawXObject( img, 10, 700, 100, 100 );
Where the last two numbers specify the size of the image to be drawn.
For similar situation, for me, with PDF 2.0.11 and a tiff file of dimensions - 1600 x 2100 the following code perfectly fit the image in A4 (portrait) size. Not sure if PDFRectangle is okay with you.
I got this example straight from PDFBOX - Example
The only thing I tweaked/introduced is:
PDRectangle.A4.getWidth(), PDRectangle.A4.getHeight()
Here is the full sample:
public static void main(String[] args) throws IOException
{
// if (args.length != 2)
// {
// System.err.println("usage: " + ImageToPDF.class.getName() + " <image> <output-file>");
// System.exit(1);
// }
String imagePath = "C:/FAX/sample.tiff";
String pdfPath = "C:/FAX/sample.pdf";
if (!pdfPath.endsWith(".pdf"))
{
System.err.println("Last argument must be the destination .pdf file");
System.exit(1);
}
try (PDDocument doc = new PDDocument())
{
PDPage page = new PDPage();
doc.addPage(page);
// createFromFile is the easiest way with an image file
// if you already have the image in a BufferedImage,
// call LosslessFactory.createFromImage() instead
PDImageXObject pdImage = PDImageXObject.createFromFile(imagePath, doc);
// draw the image at full size at (x=20, y=20)
try (PDPageContentStream contents = new PDPageContentStream(doc, page))
{
// draw the image at full size at (x=20, y=20)
contents.drawImage(pdImage, 0, 0, PDRectangle.A4.getWidth(), PDRectangle.A4.getHeight());
// to draw the image at half size at (x=20, y=20) use
// contents.drawImage(pdImage, 20, 20, pdImage.getWidth() / 2, pdImage.getHeight() / 2);
}
doc.save(pdfPath);
System.out.println("Tiff converted to PDF succussfully..!");
}
}
Hope it helps.
If your intention is an A4 sized pic on a PDF, then i guess you find the actual size of typical A4 in pixels.
Also you should be aware of the extension of the picture that you want to view like jpg, gif, or bmp ...
from what I saw in your code, the dimensions of the picture are 10 X 700 which I believe is pretty small size.
contentStream.drawImage(img, 10, 700);
And the extension of the picture is : jpg
InputStream in = new FileInputStream(new File("img.jpg"));
check those and return for more info.
that's all.
good luck'''
As per the new API 2.0.x, one can use the PDRectangle to fetch Pdf page width and height. One can use PDPageContentStream to draw the image in accordance with PDF page.
For reference:
try (PDPageContentStream contents = new PDPageContentStream(pdDocument, pdPage)) {
final PDRectangle mediaBox = pdPage.getMediaBox();
final PDImageXObject pdImage = PDImageXObject.createFromFile(image, pdDocument);
contents.drawImage(pdImage, 0, 0, mediaBox.getWidth(), mediaBox.getHeight());
}