|
Hi Bruce,
Hah, just wait, until I have time to write one simple-formatted JPEG-2000 c++ class. But now I have to write
papers.
Tony
|
|
|
|
|
Hi Tony,
Thanks your kindly answer.
I will be very appreciated to your jpeg2000 c++ sharing^^
Just, when can you finish your papers?
hehee...I would like to remind you when you finish the papers.
Thanks in advance and hope everything is smooth for your papers.
Bruce
|
|
|
|
|
When I use your code to decode M-JPEG stream, I always get some error in decoding, perhaps the JPEG frame is damaged. If any error happens when decoding, I want to catch it and skip to next frame, would you give me some help?
|
|
|
|
|
Hello,
I'd like to decode a jpeg2000 image that is stored in memory. The function ImageTranscode() allows only the transformation of a file stored on disk to another file on disk. How can transformation in memory be done?
Can I look into the sources of j2kdll?
Regards, Stefan
|
|
|
|
|
I dont know how to decode j2k file in memory by jasper. If you want that, maybe you should check jasper codec carefully and change it for your purpose. Good luck!
|
|
|
|
|
Hi Tony,
Great code. Easy to understand. I followed up line by line for the JPEG Encoder and it works great!
Do you have something similar for JPEG-2000? - I mean a single file without the regular BS.
I need to port a JPEG-2000 to a DSP processor, and an approach liker yours suits me best.
|
|
|
|
|
Thanks. I have no time to do the same work for JPEG 2000, though maybe just one month is enough. The jasper codec is hard to read.
I have to do research and write papers.
By the way, resently I read Dr. Jin Li's review paper on JPEG 2000. It clarifies the key steps in jpeg-2000, and I think it is better than other reviews on jpeg-2000.
J. Li, "Image compression - the mathematics of JPEG 2000", in MSRI modern signal processing series.
http://research.microsoft.com/~jinl/paper_2002/msri_jpeg.htm
|
|
|
|
|
Hi,Tony
I'm a new one majoring in image processing.I wrote a programme using wavelet to compress image recently.How ever,it doesn't work very well.
Can you tell me which wavelet filter you have used in your process?Any suggestions in choosing the filters you can give me?How about Daubechies filters?Please recommend some source codes or stuff to me.
Sorry,seems a lot of questions.;P
Really appreciate your help!
I want to be an expert!
|
|
|
|
|
Hi,Tony.
I'm a new one majoring in the image processing.I wrote a programme using wavelet to compress image by myself recently.However,it doesn't work very well.
Can you tell me which wavelet filter you have used in your process or give me some advices about the choosing of the filters?How about Daubechies filters?Any source code or stuff can you recommend to me?
sorry,seems a lot of questions.;P
Really appreciate your help!
|
|
|
|
|
i use the 100% quality, but the saved picture quality is so poor, that i have to give up using these code in my program.
|
|
|
|
|
You should check if your quality control is really on jpp codec. You could change the quality factor yourself.
I dont think you have the quality problem. You could try IJG codec to compare. The quality control in my implementation is same as IJG codec.
|
|
|
|
|
Even at "100%" JPEG isn't lossless. The number isn't really a percent but a "quality factor."
|
|
|
|
|
Hi,
I'm quite a newbee at c++...
I'm just a student also,
Is it possible to use the dll in a vb6 project?
and how may I do this?
I'm having difficulties finding out what is required exactly for the dll and how to call it's functions...
|
|
|
|
|
I didnot use vb. However, if it is dll, it would be easily used by other language such as vb. Good luck!
|
|
|
|
|
你的那个导出的ImageTranscode函数不是__stdcall调用方式,VB中是用不了的;;);P
|
|
|
|
|
对了,能不能做成dll vb.net能调用的呀,最好加上tif格式,而且能不打开文件就能读出文件头的信息,比如宽高,分辨率等。。谢谢。。。
|
|
|
|
|
林,你好。我刚开始接触图象压缩格式方面,所以想问一下:jpeg2000格式的图象是否在一般的浏览器上无法显示?它和JPEG相比,其算法的优点关键 何在?谢谢
|
|
|
|
|
Usually it can not be displayed on browsers. However, you could install some ie plug-ins. Jpeg 2000 has two advantages:
1. Higher compression ration, especially in low bit rate.
2. More functionalities, such as region of interests.
|
|
|
|
|
Hi Tony, I'm a programmer, but new to image manipulation in the way you have used it. I'm currently looking into using the JPEG-2000 format for viewing very large images (for diagnosic imaging, e.g. in radiology).
My question is - when opening the jp2 files, is there any way to slow the program down to show the image loading, or is the image simply converted to a bitmap and then displayed?
If this is not possible, would you recommend any code resources from which I could attempt this myself(as I need to build some kind of view that can show the image loading while reading in the image stream)?
Apologies if this seems like a dumb question! Nice job on the program
Many thanks,
Andrew
|
|
|
|
|
Hi, dont know what your question is. Sorry. Maybe you want to see how the jpeg 2000 codec works. You had better read the Jasper codes, though it is hard to understand.
|
|
|
|
|
I got 'j2kdemo' program and had it run immediately. But seems I can not get the correct result from loading a BMP file and saving as a JPG file. The image is broken anyway no matter I use 'IJG Lib' or 'CTonyJpeg Lib' as the setting in option.
Do you have idea what's happen?
Tlin
|
|
|
|
|
Hi, maybe you need check the bmp type carefully. As you know, bmp has more than formats, even including some compression format. Good luck!
|
|
|
|
|
Hi
I have a DIB to compress and send over intranet, get it from the other side and get the dib again.
How to accomplish this ?
Thanks
|
|
|
|
|
I did some project on what you want. One easy way is to try my jpp format, which can be made in small memory and avoid disk files. You just compress a dib into a jpp memory, then transmit, then decompress.
If you try jpeg 2000, you should avoid disk operations. However, the wavelet transform in jpeg2000 is much slower than dct in jpeg.
|
|
|
|
|
In your JpegDecoder, you output the GBR value,
what if I want to get the YCbCr value instead?
|
|
|
|