Keep transparency of png image with type TYPE_BYTE_INDEXED

Hi, i have a problem with a few png images. they have the type TYPE_BYTE_INDEXED. if i do any resizing or anything else with Graphics2D the transparency is lost..
here is a simple example..
        BufferedImage bi = ImageIO.read(new File(args[0]));
        double w = 450;
        double oriw = bi.getHeight();
        double orih = bi.getWidth();
        double h = (oriw/orih)*450;
        Image image = bi.getScaledInstance(450, (int)h , bi.getType());
        BufferedImage biRes = new BufferedImage((int)w,(int)h,bi.getType());
        Graphics2D bufImageGraphics = biRes.createGraphics();
        bufImageGraphics.drawImage(image, 0, 0, null);
        System.out.println(biRes.getType());
        ImageIO.write(biRes, "png", new File(args[2]));my actual java program is more complex like this..
is there anyway to "rescue" the transparency?
p.s. sorry for my bad english ;)

Try something like this:
BufferedImage biRes = new BufferedImage(bi.getColorModel(), bi.getColorModel().createCompatibleWritableRaster(w, h), bi.isAlphaPremultiplied() , null);You have to copy the color table to the new image.
The transparency data is written there.

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Keep transparency of png image with type TYPE_BYTE_INDEXED(new duke stars)

related to: http://forum.java.sun.com/thread.jspa?threadID=5178660&tstart=0
opened to assign new duke stars

Try something like this:
BufferedImage biRes = new BufferedImage(bi.getColorModel(), bi.getColorModel().createCompatibleWritableRaster(w, h), bi.isAlphaPremultiplied() , null);You have to copy the color table to the new image.
The transparency data is written there.

How do I get picture control to display PNG images with transparent background?

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Please help.

unclebump gets 5 stars for referring you to a document that I wrote.
Incidentally, I wrote it years back, for LabVIEW 7.0. A couple of notes to summarize:
The picture control doesn't "really" support transparency. However, the image data type supports masking, and stores the alpha channel, if present in your image data. So you use the "Create Mask By Alpha.vi" referenced in that document to mask out pixels whose transparency is above a certain level. It does not support partial transparency. You could try to implement your own blending algorithm based on the picture control's current pixel values, and the image data's RGB value and transparency value, but it would probably be very slow.
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Problem with reduction Of an PNG Image with transparent background

I have an PNG Image on my computer with a transparent background that I would like to reduce 50% and save it back to my computer can you tell me how to achive this?

Are you looking to reduce the size (pixel dimensions) by 50% or reduce the file size by 50%?
If you want to reduce the actual image size (pixel dimensions) you could go to Image>Image Size
and check resample image with constrain proportions and then enter 50 in the pixel dimensions at the top after setting
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Or use file Save for Web and enter 50 under the percent under image size.
As far as saving you could use File>Save As in photoshop and choose png or File>Save for Web>png
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The Graphics2D instance I'm drawing to is obtained from a BufferStrategy instance (I'm painting onto an AWT Canvas).
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You may want to check on you system and see what ImageReaders are available, it could be ImageIO is just not picking the best one, if not, then you can use getImageReaders to get an iterator of image readers, then choose the more appropriate one.

Safari on iphone won't render cgi generated png images with query strings

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it turns out that safari's handling of png is broken, the problem reproduced on both iphone and mac safaris.
in changing the format to gif, it all works okay.
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Transparency in png image not showing

Hello,
I have a Region, which needs a background and an image 'on top' of it.
I can set the background using
setStyle("-fx-background-color: #" + 123456 + ";");
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this.getChildren().addAll(rect, spiralImgView);
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Thanks

I didn't do any coding. This will tell you if it is your image:
1) Download and start JavaFX Scene Builder
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If your image is mostly transparent it's background will not be white but #1d1d1d

No Transparency on PNG image problem

I'm trying to create an ImageIcon that uses a transparent PNG image. I have set a particular colour on the image itself to be transparent in Corel PhotoPaint, and when i view the .png image that is output this colour is transparent.
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Cheers

I'm trying to create an ImageIcon that uses a transparent PNG image. I have set a particular colour on the image itself to be transparent in Corel PhotoPaint, and when i view the .png image that is output this colour is transparent.
However, when i then load this png image into my Swing app, using it as an ImageIcon, the transparent colour is no longer transparent, and the original colour can be seen in its place.
Anyone have any ideas?
Cheers

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Hi,
I have this FLA with animation and when played, the animation has alpha channel. I can’t understand why when I look in the library I see the frames without the alpha channel and also when I try to export/extract the image again the image don’t have alpha channel.
How is it that in flash this image has alpha channel and how to get it out like that into PNG?
Here is the link to download the FLA:
http://download759.mediafire.com/nb749r29220g/e0636ab0ru6ouoa/Untitled-1.fla

"when played, the animation has alpha channel"
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For those of us who may not want to download your file, please provide a more detailed describtion of everything related to this question.
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Adninjastrator

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Hi Adam,
MDM makes use of Internet Explorer quite frequently. I can imagine that this engine is also used to display images in MDM. However, Internet Explorer in version 6 does not support transparency in PNG images. That is why the black background occurs.
Since your images after upload are only saved in a binary object in the database, you should not encounter any data loss when using the same images. If you need to create variants, I would consider using Photoshop for the creation of those.
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Christian

Black background for transparent PNG images - Xcelsius 2008 SP4

Hi Experts,
I am using Xcelsius 2008 SP4. I have used Image component to show a PNG image with transparent background. When I export the flash, the image is being shown with a black background.
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pasg

Hi all,
I was facing the very same issue. I succeeded in finding a solution to it. This is happening coz of the dimension and pixels of the .png image. I imported the image in the image component, which had the dimensions, 175 x 70, and was of 9.26 kb and the black background was visible. I then changed the dimension of the image to 428 x 140, and 19.2 kb (double the size), and VOILA!! to my surprise IT WORKED !
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Try the same, I hope this helps.
Regards,
Sara

PNG Semi-Transparent background shows up with visual errors in code view in Dreamweaver CS5

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I guess you're referring to 'Design View'.
Design View is only more from a reference perspective - it doesn't render graphic elements the way it is supposed to, always.
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Btw, can you post the CSS rule you've applied to this DIV where you add the background image for the separator line?

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Photoshop CS5, is not shrinking PNG images with transparency more then I would like. Including adjusting all options from 'save for web', does anyone have any recommendations or alternatives that I could use ?

Reading between the lines, it sounds as though you need the transparency. What's not so clear is whether you need the 256 levels of transparency, nor what your use for the images is.
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hi,
i'm trying to find a way to frame images with transparent background png frames...
what i'm doing now is
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the problems with this method are:
1-depending on the width of the frame, the frame sometimes hides parts of the image (thick frame), and sometimes there is a gap between the frame and the image (thin frame).
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thanks.

Have you looked into the Border interface? If what you really want to do
is put a custom border on a component, you may be able to do it this way.
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import java.awt.*;
import java.awt.image.*;
import java.io.*;
import java.net.*;
import javax.imageio.*;
import javax.swing.*;
public class Example extends JComponent {
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}

Keep transparency of png image with type TYPE_BYTE_INDEXED

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