coobird
Resizing an index-paletted transparent PNG results in a black background
I want to resize a png file in following code:
Thumbnails.of(srcImg).size(width, height).toFile(optImg)
But all transparent background turns to black.
See the attach
What should I do?
thumbnailator-0.4.0 in sun/oracle jdk1.7
Thank you very much!
Original issue reported on code.google.com by [email protected] on 8 Nov 2012 at 4:27
Attachments:
Hi,
Thank you for reporting this issue.
I was able to reproduce the issue you have encountered with Thumbnailator 0.4.2.
The root cause is that the original image is a image which is using an indexed
palette with a specific color used for the transparent pixels. (Similar to how
transparent GIFs work)
There is no workaround for this issue (as fixing this problem will require
additional checks in the code), so there isn't anything that can be done at
this moment.
If it is possible, if you can use a PNG image with an actual alpha
(transparency) channel, then it should be able to keep the transparency
correctly.
Original comment by [email protected] on 11 Nov 2012 at 11:56
- Changed title: Resizing an index-paletted transparent PNG results in a black background
- Changed state: Accepted
- Added labels: Priority-Low
- Removed labels: Priority-Medium
I would love to see this resolved since I can't control whether the source
image has an alpha channel or not.
Let me know if there's anything I can do.
Original comment by [email protected] on 13 Feb 2013 at 10:33
Use the following with your image to replace the Transparent Pixels with White
color. It worked perfectly with me.
if( buffered.getColorModel().getTransparency() != Transparency.OPAQUE) {
int w = buffered.getWidth();
int h = buffered.getHeight();
image2 = new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB);
Graphics2D g = image2.createGraphics();
g.setColor(Color.WHITE);
g.fillRect(0,0,w,h);
g.drawRenderedImage(buffered, null);
g.dispose();
}
Thanks..
Original comment by [email protected] on 25 Feb 2013 at 9:44
I have verified that the background will turn black for both PNG and GIF files
(which have a transparent color set in their indexed pallete) using
Thumbnailator 0.4.3 running Java 7.
I will increase the priority of this issue, as it appears to affect more users
than I had initially expected.
I would like to thank everyone who has taken their time to provide input toward
this issue.
Original comment by [email protected] on 7 Apr 2013 at 8:15
- Added labels: Priority-Medium
- Removed labels: Priority-Low
Plz let the user choose what color to use as background when pngs with
transparency are converted to jpg
Original comment by [email protected] on 14 May 2013 at 6:31
I would also like to be able to choose what color is used to replace the
transparency.
Original comment by [email protected] on 4 Dec 2013 at 9:31
I have exactly the same problem. Do we have any update on this?
Original comment by [email protected] on 12 Aug 2014 at 11:25
Hi guys,
is there any update on this? I ran into the same problem. Would also like to
have an easy way to configure the resulting background color out of a
transparent image.
Original comment by [email protected] on 9 Sep 2014 at 5:00
HI
I just ran into this issue and cant seem to find a workaround.
E.g if I have a PNG and do this
File fn = new File("test.png") ;
File f = new File("test-small.png)" ;
int s = 300 ;
Thumbnails.of(fn).size(s, s).toFile(f);
The resultant file has a back background when displayed
Original comment by [email protected] on 17 Mar 2015 at 11:33
Attachments:
- [blackwire-c310-mono (1).png](https://storage.googleapis.com/google-code-attachments/thumbnailator/issue-41/comment-12/blackwire-c310-mono %281%29.png)
- 3487-300.png
Hello there,
Yes, I can confirm that the newly uploaded image also exhibits the same issue
as the image originally attached to this issue. (The image of the star)
The issue with this new image (headset) is also the same as the original image
(star) in that they are both index-paletted PNGs which specifies a specific
color to be transparent.
Original comment by [email protected] on 18 Mar 2015 at 5:25
Hi,
I'm developing an application where many users will be submitting a screenshot
taken from their computer. We are receiving a complaint that all screenshots
taken from Mac saved as PNG files are resized with color distortion. Is this
the same problem reported on this issue? Please see attached files for
original file and thumbnail generated. Is there any workaround or fix for this?
Thank you in advance.
Original comment by [email protected] on 16 Apr 2015 at 3:57
Attachments:
I tried to resizing the image on Java 6 (Linux) with Thumbnailator 0.4.8, and
was unable to reproduce the issue.
Which environment (OS, Java vendor/version) and version of Thumbnailator are
you using?
Also, could you provide the code that is being used to invoke Thumbnailator?
The code doesn't need to be exact -- I would like to know what type of input
(`BufferedImage`? `File`?) and output (`BufferedImage`? `File`?) you are
working with.
Original comment by [email protected] on 22 Apr 2015 at 1:29
This issue is also affecting me!
A fix would be appreciated
Original comment by [email protected] on 14 May 2015 at 6:56
4 years since this issue was firstly reported and no solution. Clearly thumbnailator developers don't care about this issue that's affecting lots of people.
Is there something that's wrong with the option suggested here for solving this issue: https://stackoverflow.com/questions/44383332/how-to-replace-black-background-with-white-on-image-resizing-using-thumbnailator
ie: call .addFilter(new Canvas(...., Color.WHITE))
It seems to work, is there a reason why shouldn't use this?
@theyuv, it's not clear whether the linked Stack Overflow question is using a transparent PNG that's index-paletted. This issue was filed regarding a PNG image that was using index-palette transparency.
If the original image is a PNG with an alpha channel, then the answer in the linked Stack Overflow question would work, if what you're trying to accomplish is to add a solid color background.
@coobird Thanks for the response and the clarification. It worked for my png file but I didn't check whether or not it was index-paletted.
I have found a solution for this, might help others. Please test and verify.
I replaced below code:
BufferedImage finalImage = Thumbnails.of(temp)
.size(videoWidth, videoHeight)
.asBufferedImage();
with:
BufferedImage finalImage = Thumbnails.of(temp)
.size(videoWidth, videoHeight)
.imageType(BufferedImage.TYPE_INT_ARGB)
.asBufferedImage();
Input image used was indexed 8 bit png with transparency.
I have tried many PNG configuration, with GIMP, and I don't seem to have it working, even with the Alpha Channel. Someone has a sample PNG with transparency that works for them ? I am using the latest lib also from maven
