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Phil Mood

Crop Image Background

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Hi, I use the CropImage function to insert an image from a file into a container field,

Base64Decode ( Base64Encode ( CropImage( $importpath ; myTable::img_X ; myTable::img_Y ; myTable::img_pic_width ; myTable::img_pic_height ) ) ; myTable::img_destination_fieldname )

It works perfectly but, if the XY coordinates are negatives, the background that fills the empty space is set automatically to black.


Base64Decode ( Base64Encode ( CropImage( $importpath ; -200 ; -75 ; 500 ; 250 ) ) ; myTable::img_destination_fieldname )


I use negative coordinates to position the picture inside the container.

How I can avoid the black background? Or at least set it to white/transparent.


Small update: the problem exist even with positive values. Ex.

Base64Decode ( Base64Encode ( CropImage( $importpath ; 25 ; 100; 500 ; 250 ) ) ;myTable::img_destination_fieldname )


It seems that the Crop function simply add automatically a black background to fill any empty space.

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Add this at the top

import java.awt.Color

 Then add

//add these
//or choose any other Color you prefer
//see https://docs.oracle.com/javase/7/docs/api/java/awt/Color.html
d.clearRect(0, 0, widthInt, heightInt)
//before this
d.drawImage(img, xInt*-1, yInt*-1, null)

This line/param


says it is an RGB image

If your source has transparency then you want to be using BufferedImage.TYPE_INT_ARGB, but the code to get/create transparency where you have a negtive x or y is a little more difficult...

Edited by john renfrew

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Hi John,

I am trying to obtain the same result with the function "Rotate Image" but somehow your trick doesn't work here.

Any help is really appreciated.


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Are you trying to rotate and resize at the same time?? Surely when you rotate an image there is no 'spare' to be cast as transparent? 

If you rotate a 400*300px image by 90degrees then you get a 300*400px image, or are you trying to rotate by other angles??

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Here is a new function for rotation of PNG files, which should fix your issue, if you pass it a file with no transparency or alphait returns an error to you

If you do SMGetVariable("cm") after running it you will see the color model Java thinks the file has


// RotatePNG ( imgLocation ; degrees )
// v1.0
// 19_03_12 JR

import javax.imageio.ImageIO
import java.awt.image.BufferedImage
import java.awt.Graphics2D
import java.awt.geom.AffineTransform
import java.awt.RenderingHints

isTransparent = {image, x, y ->
	pixel = image.getRGB(x,y)
	return (pixel>>24) == 0x00

containsTransparency  = { image ->
	for (i in 0..<image.getHeight()) {
		for (j in 0..<image.getWidth()) {
			if (isTransparent(image, j, i)){
				return true
			} //end if
		} //end for
	} //end for
} //end containsTransparency

containsAlphaChannel ={ image ->
	return image.getColorModel().hasAlpha()
}//end containsAlphaChannel

degrees = Double.parseDouble(degrees)
radians = Math.toRadians(degrees)
isRightAngle = degrees % 90 == 0

BufferedImage img
if (imgLocation.indexOf("://") != -1) {
	img = ImageIO.read(new URL(imgLocation))
} else {
	img = ImageIO.read(new File(imgLocation))

cm = img.getColorModel()
//check for transparency
isAlpha = containsAlphaChannel(img)
if ( !isAlpha) {
	isTransparent = containsTransparency(img)
	if ( !isTransparent){
		return 'ERROR - no transparency'
	}//end if
	return 'ERROR - no transparency'
} //end if
} catch (e) {
	return 'ERROR - unspecified'

int newWidth = Math.abs(Math.cos(radians) * img.getWidth()) + Math.abs(Math.sin(radians) * img.getHeight())
int newHeight = Math.abs(Math.cos(radians) * img.getHeight()) + Math.abs(Math.sin(radians) * img.getWidth())
at = AffineTransform.getRotateInstance(radians, img.getWidth()/2, img.getHeight()/2)

type = BufferedImage.TYPE_INT_ARGB

dest = new BufferedImage(newWidth, newHeight, type)

g2d = dest.createGraphics()
if (!isRightAngle) {
    // enable antialiasing for odd angles
    g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

g2d.setTransform(AffineTransform.getTranslateInstance((newWidth - img.getWidth()) / 2, (newHeight - img.getHeight()) / 2))
g2d.drawImage(img, at, null)

return dest

So only two parameters as you don't care about background colour

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