CODEWITHSUNDEEP
javaimage-manipulation
Maksim
Maksim

Reputation: 16941

Scaling image in java

I have a requirements to create a web service that will generate user's icon based on their initials. Similar to this Android project but on the server side using Java.

Image

The size of that image should be dynamic. I already have the code that will create a rectangle with two letters in the middle but it is not scaling the text.

Here is my code so far:

public BufferedImage getAbbreviationImage(int height, int width, String abbreviation) throws IOException {

    int centerX = width/2;
    int centerY = height/2;

    BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.SCALE_SMOOTH);

    Graphics2D g = bufferedImage.createGraphics();
    Font font = new Font("Helvetica", Font.BOLD, 90);
    g.setFont(font);
    g.setRenderingHint(
            RenderingHints.KEY_TEXT_ANTIALIASING,
            RenderingHints.VALUE_TEXT_ANTIALIAS_LCD_HRGB);

    g.setColor(Color.decode("#3f404c"));
    g.fillRect(0, 0, width, height);


    // get the bounds of the string to draw.
    FontMetrics fontMetrics = g.getFontMetrics();
    Rectangle stringBounds = fontMetrics.getStringBounds(abbreviation, g).getBounds();

    FontRenderContext renderContext = g.getFontRenderContext();
    GlyphVector glyphVector = font.createGlyphVector(renderContext, abbreviation);
    Rectangle visualBounds = glyphVector.getVisualBounds().getBounds();

    // calculate the lower left point at which to draw the string. note that this we
    // give the graphics context the y corridinate at which we want the baseline to
    // be placed. use the visual bounds height to center on in conjuction with the
    // position returned in the visual bounds. the vertical position given back in the
    // visualBounds is a negative offset from the basline of the text.
    int textX = centerX - stringBounds.width/2;
    int textY = centerY - visualBounds.height/2 - visualBounds.y;

    g.setColor(Color.WHITE);
    g.drawString(abbreviation, textX, textY);

    g.dispose();

    return bufferedImage;
}

Is there any Java library that can do something like this already so that I don't have to write my own code. If not, then what would be the best approach to scale text based on the image size?

Credits: Some of my code was take from HERE

Upvotes: 0

Views: 139

Answers (1)

LintfordPickle
LintfordPickle

Reputation: 409

You need to set the size of the font which you attach to the Graphics2D object. From the oracle docs:

public abstract void drawString(String str,
              int x,
              int y)

Renders the text of the specified String, using the current text attribute state in the Graphics2D context

You should set the size of the font you use appropriately to match the dimensions of the rectangle. Something like this:

int lFontSize = 90 * (originalRectangleWidth / newRectangleWidth);
Font font = new Font("Helvetica", Font.BOLD, lFontSize );

where:

  • 90 is the reference font size (this is what you are setting in the example)

  • originalRectangleWidth would be the size of the rectangle you use when the font looks good with size 90

  • newRectangleWidth would be the new rectangle width

References: Graphics2D (oracle ref) Font (oracle ref)

Upvotes: 2

Related Questions