Using .png as label icon

Question

I created a small program which ran great, I then needed to add a GUI so ported all my code over using NetBeans to make things a bit easier. Ive got it working great when I use jpgs but obviously that isnt the best format to use. Before, when I used pngs it worked fine, now I get a big list of errors in the console which I never would get before. Essentially the program reads the file the user selects as a bufferedimage and it also sets the label in the GUI as the selected file, or it did until creating the GUI. As I say it works fine with jpg, no issues at all so im not too sure what is happening. Its also reading it as a bufferedimage fine as im printing the filepath and bufferedimage variable to the console so can see both of those are fine, then a big list of errors which are the following:

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: [I cannot be cast to [B at java.awt.image.ColorModel.getAlpha(ColorModel.java:833) at java.awt.image.ColorModel.getRGB(ColorModel.java:878) at sun.awt.image.ImageRepresentation.convertToRGB(ImageRepresentation.java:305) at sun.awt.image.ImageRepresentation.setPixels(ImageRepresentation.java:564) at java.awt.image.AreaAveragingScaleFilter.accumPixels(AreaAveragingScaleFilter.java:213) at java.awt.image.AreaAveragingScaleFilter.setPixels(AreaAveragingScaleFilter.java:252) at sun.awt.image.OffScreenImageSource.sendPixels(OffScreenImageSource.java:102) at sun.awt.image.OffScreenImageSource.produce(OffScreenImageSource.java:187) at sun.awt.image.OffScreenImageSource.addConsumer(OffScreenImageSource.java:66) at sun.awt.image.OffScreenImageSource.startProduction(OffScreenImageSource.java:80) at java.awt.image.FilteredImageSource.startProduction(FilteredImageSource.java:183) at sun.awt.image.ImageRepresentation.startProduction(ImageRepresentation.java:727) at sun.awt.image.ImageRepresentation.drawToBufImage(ImageRepresentation.java:802) at sun.java2d.pipe.DrawImage.copyImage(DrawImage.java:1018) at sun.java2d.pipe.ValidatePipe.copyImage(ValidatePipe.java:186) at sun.java2d.SunGraphics2D.drawImage(SunGraphics2D.java:3084) at sun.java2d.SunGraphics2D.drawImage(SunGraphics2D.java:3069) at javax.swing.ImageIcon.paintIcon(ImageIcon.java:413) at sun.swing.plaf.synth.SynthIcon.paintIcon(SynthIcon.java:67) at javax.swing.plaf.synth.SynthGraphicsUtils.paintText(SynthGraphicsUtils.java:396) at javax.swing.plaf.synth.SynthLabelUI.paint(SynthLabelUI.java:213) at javax.swing.plaf.synth.SynthLabelUI.update(SynthLabelUI.java:177) at javax.swing.JComponent.paintComponent(JComponent.java:778) at javax.swing.JComponent.paint(JComponent.java:1054) at javax.swing.JComponent.paintChildren(JComponent.java:887) at javax.swing.JComponent.paint(JComponent.java:1063) at javax.swing.JComponent.paintToOffscreen(JComponent.java:5221) at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1512) at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1443) at javax.swing.RepaintManager.paint(RepaintManager.java:1236) at javax.swing.JComponent._paintImmediately(JComponent.java:5169) at javax.swing.JComponent.paintImmediately(JComponent.java:4980) at javax.swing.RepaintManager$3.run(RepaintManager.java:796) at javax.swing.RepaintManager$3.run(RepaintManager.java:784) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76) at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:784) at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:757) at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:706) at javax.swing.RepaintManager.access$1000(RepaintManager.java:62) at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1651) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:727) at java.awt.EventQueue.access$200(EventQueue.java:103) at java.awt.EventQueue$3.run(EventQueue.java:688) at java.awt.EventQueue$3.run(EventQueue.java:686) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76) at java.awt.EventQueue.dispatchEvent(EventQueue.java:697) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138) at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

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With my code for loading the icon being:

image1 = ImageIO.read(file);            
            ImageIcon imageIcon1 = new ImageIcon(image1);
            Image redInput = imageIcon1.getImage().getScaledInstance(300, 300, Image.SCALE_SMOOTH);
            imageIcon1.setImage(redInput);
            redLabel.setIcon(imageIcon1);

I only have 1 class called NewJFrame, any help would be massively appreciated!

Answer 1

Since it doesn’t seem to be an error in your code, I suggest to try to work-around this problem as you can’t change the AWT implementation.

BufferedImage img=ImageIO.read(file);
Image redInput=new AffineTransformOp(
  AffineTransform.getScaleInstance(300.0/img.getWidth(), 300.0/img.getHeight()),
  AffineTransformOp.TYPE_BICUBIC).filter(img, null);
imageIcon1= new ImageIcon(redInput, file.toString());
redLabel.setIcon(imageIcon1);

This code goes to a different path dedicated to the specialized processing of a BufferedImage. There’s no guaranty the this doesn’t encounter the same bug (as I hadn’t have your file to test it). But I think, it’s worth a try as the change to your code is rather small.

If that doesn’t work you can try the to convert the color space manually right after loading as already suggested by others:

BufferedImage img=ImageIO.read(file);
final int w = img.getWidth(), h = img.getHeight();
BufferedImage bi=new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
bi.setRGB(0, 0, w, h, img.getRGB(0, 0, w, h, null, 0, w), 0, w);
img=bi;
// proceed as normally

Answer 2

It appears you are trying to cast an int[] to a byte[].