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How to Extract an Image From an Other Using Kineticjs?

5 minutes read

To extract an image from another using KineticJS, you can create a new Kinetic.Image object and set its image to the image you want to extract from. Then, you can set its x, y, width, and height properties to specify the area of the image you want to extract. Finally, you can add the new Kinetic.Image object to the stage or layer to display it on the canvas. By doing this, you can extract specific parts of an image and display them separately using KineticJS.


What is the function of KineticJS in extracting images?

KineticJS is a JavaScript library that is used for creating interactive animations and images on websites. It provides various functions and methods to manipulate and extract images, such as loading images from external sources, resizing, rotating, and scaling them, and applying filters or effects. Additionally, KineticJS allows for image manipulation through drawing shapes and paths, adding text, and creating layers to organize and composite images. Ultimately, the function of KineticJS in extracting images is to provide a versatile and powerful tool for creating visually engaging and interactive content on websites.


How to extract images from a database using KineticJS?

To extract images from a database using KineticJS, you will need to use a server-side language like PHP or Node.js to retrieve the image data from the database and then pass it to your KineticJS script to render the images on the canvas.


Here is a basic example using PHP to retrieve an image from a MySQL database and render it using KineticJS:

  1. Create a PHP script that connects to the database, retrieves the image data, and returns it in a format that KineticJS can use (such as base64 encoding):
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<?php
// Connect to MySQL database
$mysqli = new mysqli("localhost", "username", "password", "database");

// Check connection
if ($mysqli->connect_error) {
    die("Connection failed: " . $mysqli->connect_error);
}

// Retrieve image data from database
$result = $mysqli->query("SELECT image_data FROM images WHERE id = 1");
$row = $result->fetch_assoc();
$imageData = $row['image_data'];

// Close connection
$mysqli->close();

// Return image data
echo $imageData;
?>


  1. In your KineticJS script, use an AJAX request to call the PHP script and retrieve the image data. Then create a new image object with the retrieved data and add it to the stage:
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var stage = new Kinetic.Stage({
    container: 'container',
    width: 500,
    height: 500
});

var layer = new Kinetic.Layer();

var imageObj = new Image();
imageObj.onload = function() {
    var image = new Kinetic.Image({
        x: 0,
        y: 0,
        image: imageObj,
        width: 100,
        height: 100
    });

    layer.add(image);
    stage.add(layer);
};

var url = 'get_image.php';
var xhr = new XMLHttpRequest();
xhr.open('GET', url, true);
xhr.responseType = 'blob';
xhr.onload = function() {
    var reader = new FileReader();
    reader.onload = function() {
        var dataURL = reader.result;
        imageObj.src = dataURL;
    };
    reader.readAsDataURL(xhr.response);
};
xhr.send();


  1. Make sure to replace the database connection details, table name, and column name in the PHP script with your own database information. You can also modify the SQL query to retrieve images based on specific criteria.


By following these steps, you should be able to extract images from a database using KineticJS.


How to resize the extracted image in KineticJS?

To resize an extracted image in KineticJS, you can use the setWidth() and setHeight() methods of the Kinetic.Image object.


Here's an example code snippet that shows how to extract an image from a Kinetic.Image object and resize it:

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// Get the Kinetic.Image object
var image = layer.findOne('#myImage');

// Get the extracted image data
var imageData = image.getImage();

// Create a new Kinetic.Image object with the extracted image data
var resizedImage = new Kinetic.Image({
  image: imageData,
  x: 100,
  y: 100
});

// Resize the extracted image
resizedImage.setWidth(200);
resizedImage.setHeight(100);

// Add the resized image to a layer
layer.add(resizedImage);

// Draw the layer
layer.draw();


In this code snippet, we extract the image data from the original Kinetic.Image object and create a new Kinetic.Image object with this data. Then, we resize the extracted image using the setWidth() and setHeight() methods and add it to a layer to display it. Finally, we redraw the layer to show the resized image on the stage.


How to isolate elements in an image with KineticJS?

To isolate elements in an image using KineticJS, you can follow these steps:

  1. Load your image using the Image class in KineticJS.
  2. Create a Kinetic.Image object and set the image as its source.
  3. Create a new layer and add the image object to the layer.
  4. Use the getClientRect method of the image object to get the bounding box of the image.
  5. Create a new shape object using the coordinates of the bounding box obtained in step 4.
  6. Add the shape object to the layer.
  7. Finally, add the layer to the stage.


Here is an example code snippet to show you how to isolate elements in an image with KineticJS:

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// Load the image
var img = new Image();
img.onload = function() {
  var image = new Kinetic.Image({
    image: img,
  });

  var layer = new Kinetic.Layer();
  layer.add(image);

  var rect = image.getClientRect();
  var shape = new Kinetic.Rect({
    x: rect.x,
    y: rect.y,
    width: rect.width,
    height: rect.height,
    fill: 'transparent',
    stroke: 'red',
    strokeWidth: 2,
  });

  layer.add(shape);

  stage.add(layer);
};

img.src = 'path/to/your/image.jpg';


This code will load an image, create a Kinetic.Image object with the image, get the bounding box of the image, create a shape object with the same dimensions as the bounding box, and draw a red outline around the isolated element in the image.


How to separate images in KineticJS?

To separate images in KineticJS, you can create multiple image objects and position them at different locations on the stage. Here is a step-by-step guide:

  1. Create a stage and layer:
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var stage = new Kinetic.Stage({
  container: 'container',
  width: window.innerWidth,
  height: window.innerHeight
});

var layer = new Kinetic.Layer();


  1. Create multiple image objects:
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var image1 = new Image();
image1.onload = function() {
  var imageObj1 = new Kinetic.Image({
    x: 100,
    y: 100,
    image: image1,
    width: 100,
    height: 100
  });
  layer.add(imageObj1);
  stage.add(layer);
};
image1.src = 'image1.png';

var image2 = new Image();
image2.onload = function() {
  var imageObj2 = new Kinetic.Image({
    x: 200,
    y: 200,
    image: image2,
    width: 100,
    height: 100
  });
  layer.add(imageObj2);
  stage.add(layer);
};
image2.src = 'image2.png';


  1. Add the image objects to the layer and stage:
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layer.add(imageObj1);
layer.add(imageObj2);
stage.add(layer);


  1. You can then manipulate each image object separately by using their respective Kinetic.Image objects (imageObj1, imageObj2) and set their properties as needed.


By following these steps, you can easily separate and position multiple images in KineticJS.

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