# \[Java\] Deblur PSF and Wiener - all black result

**URL:** <https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249>\
**Category:** Uncategorized\
**Tags:** valgrind\
**Created:** [December 10, 2020, 2:13pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249 "2020-12-10T14:13:14Z")\
**Posts on this page:** 20\
**Page:** 1

<div class="post-metadata">

**Author:** ![natlu2809](https://avatars.discourse-cdn.com/v4/letter/n/9fc29f/32.png) [@natlu2809](https://forum.opencv.org/u/natlu2809)\
**Post date:** [December 10, 2020, 2:13pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/1 "2020-12-10T14:13:15Z")

</div>

Hi,

Thanks to OpenCV for the comprehensive and very useful libraries - they’ve enabled me to do some (hobby) work I’ve been planning to do a for a long time.

I’ve create a small proof of concept app in Java with JavaFX, OpenCV 4.5.0\_pre, and JRawIO to read jpgs, pngs and NEF files. I’ve successfully followed tutorials and C++ samples to build face detection, FFT, shapening. Im trying now to do PSF and Wiener “deblur”, as per [[OpenCV: Out-of-focus Deblur Filter](https://docs.opencv.org/master/de/d3c/tutorial_out_of_focus_deblur_filter.html)].

However, no matter how much I pore over the code, debug, look at source and tutorials, surf and search this forum and the wider web, I cannot manage to get an image back after the process runs through - all I get back is a black image, no recognisable features of any kind.

I’ve checked for normalisation, ensured DFTs are scaled (or not), have ensured/worked out how to use absdiff() and pow() for the wiener filter code, how to Core.divide and mulSpectrums, but nothing I do or change or investigate produces anything but a full black image result.

I’ve changed PSF to kernels of the same size, looked at filter2D, created extra intermediate mats rather than use them “in place” for some of the calls, and tried to visualise and ensure that the Mats created in calcPSF and calcWiener are what they should be (to me) and it seems that the black image arises when I do the idft() and split().

So, I’m stuck. Can anyone point me in a new direction and happy to show some code if it will help.

Thanks!

---

<div class="post-metadata">

**Author:** ![berak](https://avatars.discourse-cdn.com/v4/letter/b/85f322/32.png) [@berak](https://forum.opencv.org/u/berak)\
**Post date:** [December 10, 2020, 2:37pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/2 "2020-12-10T14:37:17Z")

</div>

i guess, we cannot help, without seing your actual code, so please edit your question, and add it there, thank you.

---

<div class="post-metadata">

**Author:** ![natlu2809](https://avatars.discourse-cdn.com/v4/letter/n/9fc29f/32.png) [@natlu2809](https://forum.opencv.org/u/natlu2809)\
**Post date:** [December 10, 2020, 4:16pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/3 "2020-12-10T16:16:29Z")

</div>

Start at deblue() then doDeBlur - it calls calcPSF, calcWiener and filter2DFreq  
Class these methods are contains instance variables for an arrayList of planes, an imageMat and complexImage - you’ll see calls for getPlanes() etc in various places. Ive include some utility code for completenesss e.g. convertAndNormalize() - these methods are used elsewhere and work successfully.

Thanks again for any insights.

> /\*\*
> 
> - do PSF and Wiener deblurring  
> \*/  
> public void deblur() {
> 
> }
> 
> private void updateThisImageMat(boolean isColour) {
> 
> ```
> //@TODO - relaod imageMat - other operations may have manipulatd or reset it
> long oldTime = System.currentTimeMillis();
> if ( isRawFile() ){
> //if loadImage() not already called
> if ( null == getRawReader().getMat()) {
> setRawReader( SceneImageUtils.getRawReaderFromFile(getImageLocation(), getExtension()) );
> }
>            
> if (isColour) {
> setImageMat( (Mat)getRawReader().getMat() );
> } else {
>                    
> }
>                    
> } else {
>            
> if ( isColour ) {
> setImageMat( Imgcodecs.imread( imageLocation ) );
> }else {
> setImageMat( Imgcodecs.imread( getImageLocation(), Imgcodecs.IMREAD_GRAYSCALE ) );
> }
>            
> }
> SceneImageUtils.print("Updated image mat in (ms) " + (System.currentTimeMillis()-oldTime));
> 
> ```
> 
> }
> 
> /\*\*
> 
> - calculate a PSF, use to create wiener filter, multiply with BW version of
> 
> - image, convert and normalise
> 
> - 
> - @return  
> \*/  
> private Mat doDeBlur() {
> 
> }
> 
> private Mat calcPSF(Size filterSize, int radius)  
> {
> 
> Mat psf = new Mat(filterSize, CvType.CV\_32F, new Scalar(0) );  
> Point centrePoint = new Point(filterSize.width / 2, filterSize.height / 2);
> 
> Imgproc.circle(psf, centrePoint, radius, new Scalar(255), -1, 8);  
> Scalar summa = Core.sumElems(psf);
> 
> Mat done = new Mat(filterSize, CvType.CV\_32F, new Scalar(0));
> 
> Core.divide( summa.val[0], psf, done);
> 
> return done;  
> }
> 
> /\*\*  
> \*
> 
> - @param calculatedPSF input PSF as a mat
> 
> - @param invertedSNR - already inverted SNR
> 
> - @return  
> \*/  
> private Mat calcWienerFilter( Mat calculatedPSF, double invertedSNR)  
> {  
> clearPlanesAndTransforms();
> 
> private Mat filter2DFreq( Mat inputImg, Mat H)  
> {
> 
> //clear and prep first instance planes and complex images  
> clearPlanesAndTransforms();  
> prepPlanesAndTransforms(inputImg);
> 
> //merge planes and run DFT so it can be inverted and displayed  
> mergeAndDFT(true);
> 
> // do the filtering  
> Mat complexIH = multiplyFrequencies(H);
> 
> //invert for re-display  
> invertFFT( complexIH );
> 
> return getPlanes().get(0);
> 
> }
> 
> private Mat getBWMat() {
> 
> ```
> Mat greyScaleMat = new Mat();
> 
> if (null != getImageMat() ) {
> greyScaleMat = new Mat(getImageMat().size(), CvType.CV_8UC1 );
> Imgproc.cvtColor(getImageMat(), greyScaleMat, Imgproc.COLOR_BGR2GRAY );
> } else {
> greyScaleMat = null;
> }
>    
> return greyScaleMat;
> 
> ```
> 
> }
> 
> private Mat convertAndNormalize(Mat imgOut) {
> 
> Mat dst = new Mat();
> 
> Core.normalize(imgOut, dst, 0, 255, Core.NORM\_MINMAX);
> 
> dst.convertTo(dst, CvType.CV\_32F);  
> return dst;  
> }
> 
> /\*\*
> 
> - set detected image to from input Mat, for common formats and NEF raw images
> - 
> - @param imageMat
> - @param extension
> 
> > \*/  
> > private void updateThisDetectedImage(Mat imageMat, String extension) {  
> > // TODO Auto-generated method stub  
> > long oldTime = System.currentTimeMillis();  
> > SceneImageUtils.print(“Updating detected image”);
> 
> ```
> if ( isRawExtension( extension )) {
> setDetectedImage( ImageConverter.mat2img(imageMat) );
> } else {
> setDetectedImage( ImageConverter.mat2img(imageMat, extension ) );
> }
>    
> SceneImageUtils.print("Updated detected image from Mat in (ms)" + (System.currentTimeMillis()-oldTime) );
> 
> ```
> 
> }

---

<div class="post-metadata">

**Author:** ![crackwitz](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/crackwitz/32/14_2.png) [@crackwitz](https://forum.opencv.org/u/crackwitz)\
**Post date:** [December 10, 2020, 4:50pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/4 "2020-12-10T16:50:26Z")

</div>

what is the earliest point in your code at which you notice a Mat/image being black when you expect it to have content?

---

<div class="post-metadata">

**Author:** ![natlu2809](https://avatars.discourse-cdn.com/v4/letter/n/9fc29f/32.png) [@natlu2809](https://forum.opencv.org/u/natlu2809)\
**Post date:** [December 10, 2020, 5:22pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/5 "2020-12-10T17:22:37Z")

</div>

Thanks for helping crackwitz.

Just confirmed that it is at the call to calcPSF - if I convertAndNormalize just the output from that call I get a black image, and the same if I convertAndNormalize() the output of calcWienerFilter()

i.e.  
Mat psf = calcPSF( roi.size(), getPsfRadius() );  
Mat done = convertAndNormalize(psf);

should the psf show up as a (more or less) white circle on a black background if it is displayed?

---

<div class="post-metadata">

**Author:** ![natlu2809](https://avatars.discourse-cdn.com/v4/letter/n/9fc29f/32.png) [@natlu2809](https://forum.opencv.org/u/natlu2809)\
**Post date:** [December 10, 2020, 6:11pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/6 "2020-12-10T18:11:26Z")

</div>

and to go a little, further (if the thinking is that displaying psf or the wienerFilter result as black is OK), if I delve into filter2DFreq and

1. display the result of the mergeAndDFT call I see a grey image (a DFT that is not optimeised for display?)
2. if I display the result of the call to multiplyFrequencies() I see a black image.

Heres the relevant code for those tests

1. grey image

> mergeAndDFT(true);  
> Core.split(getComplexImage(),getPlanes();  
> return getPlanes().get(0);

1. black image

> mergeAndDFT(true);  
> Mat complexIH = multiplyFrequencies(H);  
> return getPlanes().get(0);

Heres the code for those mergeAndDFt and multiplyFrequencies calls (sorry, I didn’t include in the first sample of code)

> private void mergeAndDFT(boolean forInverse) {  
> // prepare a complex image for performing the dft
> 
> Core.merge( getPlanes(), getComplexImage());
> 
> // dft it  
> if (forInverse) {  
> Core.dft( getComplexImage(), getComplexImage() , Core.DFT\_SCALE );
> 
> } else {  
> Core.dft( getComplexImage(), getComplexImage() );  
> }
> 
> }
> 
> private Mat multiplyFrequencies(Mat H) {  
> List newPlanes = new ArrayList\<\>();
> 
> Mat padded = H.clone();  
> newPlanes.add( padded );  
> newPlanes.add( Mat.zeros( H.size(), CvType.CV\_32F ) );
> 
> Mat complexH = new Mat(H.size(), CvType.CV\_32F);  
> Core.merge( newPlanes, complexH );
> 
> Mat complexIH = new Mat( getComplexImage().size(), CvType.CV\_32F );  
> Core.mulSpectrums( getComplexImage(), complexH, complexIH, 0);  
> return complexIH;  
> }

---

<div class="post-metadata">

**Author:** ![berak](https://avatars.discourse-cdn.com/v4/letter/b/85f322/32.png) [@berak](https://forum.opencv.org/u/berak)\
**Post date:** [December 10, 2020, 6:41pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/7 "2020-12-10T18:41:37Z")

</div>

i’m suspecting a problem with types here, like applying filtering on CV\_8U(integer!) images, and thus saturating results to 0.

i see you pre-allocating output Mat’s all over, and you probably expect them to have the type / size you wanted, but quite often, this will be not so, and will deceive you.

e.g, if you use divide() on an uchar image, the result will also will be uchar, and your preallocated float Mat will just be discarded / reallocated to something you did not expect

example:

> [@natlu2809](#):
>
> Mat complexH = new Mat(H.size(), CvType.CV\_32F);  
> Core.merge( newPlanes, complexH );

if at all, type should be CvType.CV\_32FC2 (2 channels !)

so:

- don’t pre-allocate outputs (again, it will only fool you). use `new Mat()` for output type
- explicitly `convertTo()` your _input_ to float as early as possible
- actually _check_ types after suspicious operations
- visualize every step in your program

---

<div class="post-metadata">

**Author:** ![natlu2809](https://avatars.discourse-cdn.com/v4/letter/n/9fc29f/32.png) [@natlu2809](https://forum.opencv.org/u/natlu2809)\
**Post date:** [December 10, 2020, 9:07pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/8 "2020-12-10T21:07:27Z")

</div>

thanks Berak, I’ll take your advices and try some things out, and report back. Progress!

---

<div class="post-metadata">

**Author:** ![natlu2809](https://avatars.discourse-cdn.com/v4/letter/n/9fc29f/32.png) [@natlu2809](https://forum.opencv.org/u/natlu2809)\
**Post date:** [December 11, 2020, 11:28am UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/9 "2020-12-11T11:28:40Z")

</div>

A quick change leads to a surprising result - for me at least. Following the idea that I use

> new Mat()

my calcPSF function with some logging is now telling me I have an empty Mat for the PSF, is this correct?

FYI, When I inspect the psf object just before the return I see  
“Mat [-1\*-1\*CV\_8UC1, isCont=false, isSubmat=false, nativeObj=0x7f4adc004680, dataAddr=0x0]”

> private Mat calcPSF(Size filterSize, int radius)  
> {
> 
> Mat psf = new Mat();  
> Point centrePoint = new Point(filterSize.width / 2, filterSize.height / 2);
> 
> Imgproc.circle(psf, centrePoint, radius, new Scalar(255), -1, 8);  
> Scalar summa = Core.sumElems(psf);
> 
> Core.divide( summa.val[0], psf, psf);
> 
> SceneImageUtils.print("Empty PSF? : " + psf.empty() );
> 
> return psf;  
> }

---

<div class="post-metadata">

**Author:** ![berak](https://avatars.discourse-cdn.com/v4/letter/b/85f322/32.png) [@berak](https://forum.opencv.org/u/berak)\
**Post date:** [December 11, 2020, 11:34am UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/10 "2020-12-11T11:34:31Z")

</div>

sorry for the confusion, i meant the output Mat’s  
(from an opencv function, like divide()) before.

here, you still need to properly allocate it, like you had it in the prev. version:

```
Mat psf = new Mat(filterSize, CvType.CV_32F, new Scalar(0) );
```

---

<div class="post-metadata">

**Author:** ![natlu2809](https://avatars.discourse-cdn.com/v4/letter/n/9fc29f/32.png) [@natlu2809](https://forum.opencv.org/u/natlu2809)\
**Post date:** [December 11, 2020, 4:29pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/11 "2020-12-11T16:29:54Z")

</div>

ok, thanks, appreciate your continued attention!

---

<div class="post-metadata">

**Author:** ![natlu2809](https://avatars.discourse-cdn.com/v4/letter/n/9fc29f/32.png) [@natlu2809](https://forum.opencv.org/u/natlu2809)\
**Post date:** [December 23, 2020, 12:26pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/12 "2020-12-23T12:26:03Z")

</div>

Just to let you know Ive confirmed so far  
I can visualise the calcPSF output Mat  
Cant visualise the calcWiener output Mat - I see black image but expect, to see _something_ else that would combine with the image in some way  
Confirm that dft and idft work as expected.

Have followed advice and tried variations in places, but still not getting a wiener function processed image as output. Haven’t given up yet though, but will take more time now to try and resolve. A break and fresh eyes may help after all!

---

<div class="post-metadata">

**Author:** ![natlu2809](https://avatars.discourse-cdn.com/v4/letter/n/9fc29f/32.png) [@natlu2809](https://forum.opencv.org/u/natlu2809)\
**Post date:** [December 30, 2020, 12:40pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/13 "2020-12-30T12:40:13Z")

</div>

More work refactoring means I think I can say that the Mat multiplication code I have is causing the issue (or the code that generates the input Wiener filter - which I still cannot visualise). I am banging my head against a wall though I feel, as no amount of switching Mat creation methods or chaining together (or not) intermediate objects seems to be helping me get closer to resolving.

I have since done a build of opencv 4.5.1 in order to see if the sample "example\_tutorial\_out\_of\_focus\_deblur\_filter " code works, but it is giving me either a core dump with a png file, or an “ERROR : Image cannot be loaded…!!” with jpg files.

i.e.

> ./example\_tutorial\_out\_of\_focus\_deblur\_filter -image=./eve.jpg  
> 2018-07-12  
> DeBlur\_v8  
> You will learn how to recover an out-of-focus image by Wiener filter  
> ERROR : Image cannot be loaded…!!

or

> ./example\_tutorial\_out\_of\_focus\_deblur\_filter -image=./lena.png  
> 2018-07-12  
> DeBlur\_v8  
> You will learn how to recover an out-of-focus image by Wiener filter  
> Segmentation fault (core dumped)

valgrind on the lena.png call shows the following:

> ==52144== Use of uninitialised value of size 8  
> ==52144== at 0x77E6126: jpeg\_CreateCompress (in /usr/lib/libjpeg.so.8.2.2)  
> ==52144== by 0x486D859: cv::JpegEncoder::write(cv::Mat const&, std::vector\<int, std::allocator \> const&) (in /home/name/git/opencv\_4.5.0\_pre/build/lib/libopencv\_imgcode  
> cs.so.4.5.1)  
> ==52144== by 0x486310F: cv::imwrite(std::\_\_cxx11::basic\_string\<char, std::char\_traits, std::allocator \> const&, cv::\_InputArray const&, std::vector\<int, std::allo  
> cator \> const&) (in /home/name/git/opencv\_4.5.0\_pre/build/lib/libopencv\_imgcodecs.so.4.5.1)  
> ==52144== by 0x10AA72: main (in /home/name/git/opencv\_4.5.0\_pre/build/bin/example\_tutorial\_out\_of\_focus\_deblur\_filter)  
> ==52144==  
> ==52144== Invalid write of size 4  
> ==52144== at 0x77E6126: jpeg\_CreateCompress (in /usr/lib/libjpeg.so.8.2.2)  
> ==52144== by 0x486D859: cv::JpegEncoder::write(cv::Mat const&, std::vector\<int, std::allocator \> const&) (in /home/name/git/opencv\_4.5.0\_pre/build/lib/libopencv\_imgcode  
> cs.so.4.5.1)  
> ==52144== by 0x486310F: cv::imwrite(std::\_\_cxx11::basic\_string\<char, std::char\_traits, std::allocator \> const&, cv::\_InputArray const&, std::vector\<int, std::allo  
> cator \> const&) (in /home/name/git/opencv\_4.5.0\_pre/build/lib/libopencv\_imgcodecs.so.4.5.1)  
> ==52144== by 0x10AA72: main (in /home/name/git/opencv\_4.5.0\_pre/build/bin/example\_tutorial\_out\_of\_focus\_deblur\_filter)  
> ==52144== Address 0x679 is not stack’d, malloc’d or (recently) free’d  
> ==52144==  
> ==52144==  
> ==52144== Process terminating with default action of signal 11 (SIGSEGV): dumping core  
> ==52144== Access not within mapped region at address 0x679  
> ==52144== at 0x77E6126: jpeg\_CreateCompress (in /usr/lib/libjpeg.so.8.2.2)  
> ==52144== by 0x486D859: cv::JpegEncoder::write(cv::Mat const&, std::vector\<int, std::allocator \> const&) (in /home/name/git/opencv\_4.5.0\_pre/build/lib/libopencv\_imgcode  
> cs.so.4.5.1)  
> ==52144== by 0x486310F: cv::imwrite(std::\_\_cxx11::basic\_string\<char, std::char\_traits, std::allocator \> const&, cv::\_InputArray const&, std::vector\<int, std::allo  
> cator \> const&) (in /home/name/git/opencv\_4.5.0\_pre/build/lib/libopencv\_imgcodecs.so.4.5.1)  
> ==52144== by 0x10AA72: main (in /home/name/git/opencv\_4.5.0\_pre/build/bin/example\_tutorial\_out\_of\_focus\_deblur\_filter)

The image files are:

> file ./eve.jpg  
> ./eve.jpg: JPEG image data, JFIF standard 1.01, resolution (DPI), density 300x300, segment length 16, Exif Standard: [TIFF image data, little-endian, direntries=13, manufacturer  
> =Nokia, model=N70-1, orientation=upper-left, xresolution=182, yresolution=190, resolutionunit=2, software=darktable 3.2.1, datetime=2020:12:30 11:57:42], baseline, precision 8,  
> 1024x768, components 3

and

> file ./lena.png  
> ./lena.png: PNG image data, 512 x 512, 8-bit/color RGB, non-interlaced

NB: I suspect the cause of the problem (from the valgrind output) here is that during the build I had errors with various .so, for example:

> /usr/lib/x86\_64-linux-gnu/libjpeg.so

and other libs for png, webp, tiff etc.  
I created symlinks to the relevant libs in /usr/lib in order to get the build to complete.

But why when running with lena.png is libjpeg.so being used? Why is the jpg file not loading? (I created both files with Darktable, converting from colour versions).

I am running Manjaro 20.1

> Linux host 5.8.18-1-MANJARO #1 SMP PREEMPT Sun Nov 1 14:10:04 UTC 2020 x86\_64 GNU/Linux

---

<div class="post-metadata">

**Author:** ![crackwitz](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/crackwitz/32/14_2.png) [@crackwitz](https://forum.opencv.org/u/crackwitz)\
**Post date:** [December 30, 2020, 5:56pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/14 "2020-12-30T17:56:41Z")

</div>

a problem reading simple png/jpeg files? that’s curious! I’ve never actually had any problems with OpenCV reading picture files, but others sometimes do. I would agree with your determination that it’s some “DLL hell” situation.

OpenCV likely loads any and all libraries regardless of actual use. and in your case it seems to pick up the wrong shared objects.

---

<div class="post-metadata">

**Author:** ![natlu2809](https://avatars.discourse-cdn.com/v4/letter/n/9fc29f/32.png) [@natlu2809](https://forum.opencv.org/u/natlu2809)\
**Post date:** [December 30, 2020, 6:37pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/15 "2020-12-30T18:37:41Z")

</div>

it is peculiar. I checked with ldd the linked libraries for the java native lib I reference in eclipse for java development and the sample program - and they are the same. Some extra logging in the sample indeed shows that the jpg file after imread is empty, and with the png file, processing continues until the attempt to write the result.jpg file.

I will keep looking.

---

<div class="post-metadata">

**Author:** ![natlu2809](https://avatars.discourse-cdn.com/v4/letter/n/9fc29f/32.png) [@natlu2809](https://forum.opencv.org/u/natlu2809)\
**Post date:** [December 30, 2020, 8:29pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/16 "2020-12-30T20:29:52Z")

</div>

FYI, I turned WITH\_JPEG and WITH\_PNG off and BUILD\_JPEG and BUILD\_PNG on and rebuilt. Now the code doesn’t load either jpeg or png files!

Other samples like `porting_anisotropic_image_segmentation_gapi.cpp` that load a jpeg and `BasicLinearTransformsTrackbar` also fail. The former with the same

> ERROR : Image cannot be loaded…!!

and the latter with

> what(): OpenCV(4.5.1-pre) /home/ultan/git/opencv\_4.5.0\_pre/modules/highgui/src/window.cpp:376: error: (-215:Assertion failed) size.width\>0 && size.height\>0 in function ‘imshow’

Aborted (core dumped)

---

<div class="post-metadata">

**Author:** ![natlu2809](https://avatars.discourse-cdn.com/v4/letter/n/9fc29f/32.png) [@natlu2809](https://forum.opencv.org/u/natlu2809)\
**Post date:** [December 31, 2020, 1:11pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/17 "2020-12-31T13:11:16Z")

</div>

I give up now!

I installed Ubuntu 20.10 in Virtualbox, download the latest git code, ran a build (only inlcuded samples to be built - everything else the default build) and executed the sample code again, and I still get the error that it cannot read the jpg or png files I give it.

My version\_string is:

> “\n”  
> “General configuration for OpenCV 4.5.1-dev =====================================\n”  
> " Version control: 4.5.1-35-gbec7b297ed\n"  
> “\n”  
> " Platform:\n"  
> " Timestamp: 2020-12-30T22:13:36Z\n"  
> " Host: Linux 5.8.0-33-generic x86\_64\n"  
> " CMake: 3.16.3\n"  
> " CMake generator: Unix Makefiles\n"  
> " CMake build tool: /usr/bin/gmake\n"  
> " Configuration: Release\n"  
> “\n”  
> " CPU/HW features:\n"  
> " Baseline: SSE SSE2 SSE3\n"  
> " requested: SSE3\n"  
> " Dispatched code generation: SSE4\_1 SSE4\_2 FP16 AVX AVX2 AVX512\_SKX\n"  
> " requested: SSE4\_1 SSE4\_2 AVX FP16 AVX2 AVX512\_SKX\n"  
> " SSE4\_1 (17 files): + SSSE3 SSE4\_1\n"  
> " SSE4\_2 (2 files): + SSSE3 SSE4\_1 POPCNT SSE4\_2\n"  
> " FP16 (1 files): + SSSE3 SSE4\_1 POPCNT SSE4\_2 FP16 AVX\n"  
> " AVX (5 files): + SSSE3 SSE4\_1 POPCNT SSE4\_2 AVX\n"  
> " AVX2 (31 files): + SSSE3 SSE4\_1 POPCNT SSE4\_2 FP16 FMA3 AVX AVX2\n"  
> " AVX512\_SKX (7 files): + SSSE3 SSE4\_1 POPCNT SSE4\_2 FP16 FMA3 AVX AVX2 AVX\_512F AVX512\_COMMON AVX512\_  
> SKX\n"  
> “\n”  
> " C/C++:\n"  
> " Built as dynamic libs?: YES\n"  
> " C++ standard: 11\n"  
> " C++ Compiler: /usr/bin/c++ (ver 10.2.0)\n"  
> " C++ flags (Release): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=ad  
> dress -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpoint  
> er-arith -Wshadow -Wsign-promo -Wuninitialized -Wsuggest-override -Wno-delete-non-virtual-dtor -Wno-comment -Wim  
> plicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer  
> -ffunction-sections -fdata-sections -msse -msse2 -msse3 -fvisibility=hidden -fvisibility-inlines-hidden -O3 -D  
> NDEBUG -DNDEBUG\n"  
> " C++ flags (Debug): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=ad  
> dress -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpoint  
> er-arith -Wshadow -Wsign-promo -Wuninitialized -Wsuggest-override -Wno-delete-non-virtual-dtor -Wno-comment -Wim  
> plicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer  
> -ffunction-sections -fdata-sections -msse -msse2 -msse3 -fvisibility=hidden -fvisibility-inlines-hidden -g -O  
> 0 -DDEBUG -D\_DEBUG\n"  
> " C Compiler: /usr/bin/cc\n"  
> " C flags (Release): -fsigned-char -W -Wall -Werror=return-type -Werror=address -Werror=sequence-po  
> int -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Wi  
> nit-self -Wpointer-arith -Wshadow -Wuninitialized -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fd  
> iagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -msse -  
> msse2 -msse3 -fvisibility=hidden -O3 -DNDEBUG -DNDEBUG\n"  
> " C flags (Debug): -fsigned-char -W -Wall -Werror=return-type -Werror=address -Werror=sequence-po  
> int -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Wi  
> nit-self -Wpointer-arith -Wshadow -Wuninitialized -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fd  
> iagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -msse -  
> msse2 -msse3 -fvisibility=hidden -g -O0 -DDEBUG -D\_DEBUG\n"  
> " Linker flags (Release): -Wl,–exclude-libs,libippicv.a -Wl,–exclude-libs,libippiw.a -Wl,–gc-sectio  
> ns -Wl,–as-needed \n"  
> " Linker flags (Debug): -Wl,–exclude-libs,libippicv.a -Wl,–exclude-libs,libippiw.a -Wl,–gc-sectio  
> ns -Wl,–as-needed \n"  
> " ccache: NO\n"  
> " Precompiled headers: NO\n"  
> " Extra dependencies: dl m pthread rt\n"  
> " 3rdparty dependencies:\n"  
> “\n”  
> " OpenCV modules:\n"  
> " To be built: calib3d core dnn features2d flann gapi highgui imgcodecs imgproc ml objdetect  
> photo stitching ts video videoio\n"  
> " Disabled: world\n"  
> " Disabled by dependency: -\n"  
> " Unavailable: java python2 python3\n"  
> " Applications: tests perf\_tests examples apps\n"  
> " Documentation: NO\n"  
> " Non-free algorithms: NO\n"  
> “\n”  
> " GUI: \n"  
> " GTK+: NO\n"  
> " VTK support: NO\n"  
> “\n”  
> " Media I/O: \n"  
> " ZLib: zlib (ver 1.2.11)\n"  
> " JPEG: libjpeg-turbo (ver 2.0.6-62)\n"  
> " WEBP: build (ver encoder: 0x020f)\n"  
> " PNG: build (ver 1.6.37)\n"  
> " TIFF: build (ver 42 - 4.0.10)\n"  
> " JPEG 2000: build (ver 2.3.1)\n"  
> " OpenEXR: build (ver 2.3.0)\n"  
> " HDR: YES\n"  
> " SUNRASTER: YES\n"  
> " PXM: YES\n"  
> " PFM: YES\n"  
> “\n”  
> " Video I/O:\n"  
> " DC1394: NO\n"  
> " FFMPEG: NO\n"  
> " avcodec: NO\n"  
> " avformat: NO\n"  
> " avutil: NO\n"  
> " swscale: NO\n"  
> " avresample: NO\n"  
> " GStreamer: NO\n"  
> " v4l/v4l2: YES (linux/videodev2.h)\n"  
> “\n”  
> " Parallel framework: pthreads\n"  
> “\n”  
> " Trace: YES (with Intel ITT)\n"  
> “\n”  
> " Other third-party libraries:\n"  
> " Intel IPP: 2020.0.0 Gold [2020.0.0]\n"  
> " at: /home/name/git/opencv/build/3rdparty/ippicv/ippicv\_lnx/icv\n"  
> " Intel IPP IW: sources (2020.0.0)\n"  
> " at: /home/name/git/opencv/build/3rdparty/ippicv/ippicv\_lnx/iw\n"  
> " Lapack: NO\n"  
> " Eigen: NO\n"  
> " Custom HAL: NO\n"  
> " Protobuf: build (3.5.1)\n"  
> “\n”  
> " OpenCL: YES (no extra features)\n"  
> " Include path: /home/name/git/opencv/3rdparty/include/opencl/1.2\n"  
> " Link libraries: Dynamic load\n"  
> “\n”  
> " Python (for build): /usr/bin/python3\n"  
> “\n”  
> " Java: \n"  
> " ant: NO\n"  
> " JNI: NO\n"  
> " Java wrappers: NO\n"  
> " Java tests: NO\n"  
> “\n”  
> " Install to: /usr/local\n"  
> “-----------------------------------------------------------------\n”  
> “\n”

---

<div class="post-metadata">

**Author:** ![crackwitz](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/crackwitz/32/14_2.png) [@crackwitz](https://forum.opencv.org/u/crackwitz)\
**Post date:** [December 31, 2020, 1:30pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/18 "2020-12-31T13:30:38Z")

</div>

the code on the deblur tutorial page?

try the simplest possible code that only contains imread, and maybe imshow and waitKey. hardcode the path to the file.

---

<div class="post-metadata">

**Author:** ![natlu2809](https://avatars.discourse-cdn.com/v4/letter/n/9fc29f/32.png) [@natlu2809](https://forum.opencv.org/u/natlu2809)\
**Post date:** [December 31, 2020, 10:05pm UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/19 "2020-12-31T22:05:59Z")

</div>

Thanks for helping.

Bizarrely - I wrote the simple code you suggested and it worked - but the only thing that I effectively changed was the directory where the jpg was (_I copied the code from the main() of the out\_of\_focus\_deblur\_filter and simplified it with hardcoded path, imread and imwrite_).

In the case where it doesn’t work it is in ~/Pictures. In the case where it does work, it is in the same dir where the built executable is (~/git/opencv/build/bin). The jpg in each dir has the same user:group and permissions (744). The out\_of\_focus\_deblur\_filter code also works where the jpg is in the same directory as the executable.

This is in my fresh ubuntu install. In Manjaro this test does not work at all.

Ubuntu is

> Linux hostname 5.8.0-33-generic #36-Ubuntu SMP Wed Dec 9 09:14:40 UTC 2020 x86\_64 x86\_64 x86\_64 GNU/Linux

Manjaro is

> Linux hostname 5.9.16-1-MANJARO #1 SMP PREEMPT Mon Dec 21 22:00:46 UTC 2020 x86\_64 GNU/Linux

In any case, this just proves that my java code should work and its not a platform or library thing (I can read jpgs with imread in java OK, its the wiener code Ive written thats messing things up).

Happy New Year by the way, I hope I don’t get any responses from you tonight or tomorrow, and I appreciate your attention today!

---

<div class="post-metadata">

**Author:** ![crackwitz](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/crackwitz/32/14_2.png) [@crackwitz](https://forum.opencv.org/u/crackwitz)\
**Post date:** [January 1, 2021, 4:12am UTC](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249/20 "2021-01-01T04:12:23Z")

</div>

say, are you literally giving the path as “~/Pictures/…”?

the ~ is a special thing that needs to be explicitly resolved. it doesn’t “just work”. shells do that automatically but it’s not an integral notion of file systems.

[Next page](https://forum.opencv.org/t/java-deblur-psf-and-wiener-all-black-result/249.md?page=2)