How do I remove line artifacts from an image and why are they caused?

I'm using CT images and I received a similar artifact to the one I have attached. Can someone please tell me why it is caused and how I can remove it? Prior to this, I blurred the image, could that be a cause? Do let me know, thanks in advance!

[Benjamin Kraus]

Some questions that will help others help you better:

• In what format is the raw (original) image stored?
• How did you load the data into MATLAB (imread or some other command)?
• Does the line shows up when you are viewing the image in MATLAB, or only when you export?
• If it shows up when you are viewing in MATLAB, how are you viewing the image?
• If it is only upon export, are you exporting directly to PNG or are you exporting to PDF?
• How are you exporting the image from MATLAB to PNG (imwrite, print, saveas or some other approach)?

[JayJay]

This is actually just a sample image I found online. Unfortunately, I cannot share the image that I'm using in my program. However, my image in MATLAB shows this line artifact, and when I export it to a png/jpeg format using the 'PRINT' function, the artifacts still show up

[JayJay]

To answer your questions:

• The raw image is a CT image, not exactly sure of the exact format. However, when I performed the same for images in the X and Z directions, I did not get this artifact, it arises only in the Y direction
• Using sprintf
• It shows up in both cases
• Viewing the image using 'imagesc'. As I mentioned before, it was not a problem in the other directions (X and Z)
• It is upon export too. I exported it using the print function in the JPEG format
• Print

Thanks!!!

[Walter Roberson]

sprintf does not load images. Are you calling imread() or dicomread() or Tiff()

[JayJay]

Neither. I am just calling the files from a location on my computer using sprintf and setting the directorypath as the place where the images are stored. I'm loading CT images

[Walter Roberson]

Are you using load()? Or importdata()? Or readtable() or xlsread()?

sprintf only constructs character vectors and never ever reads from disk itself.

[JayJay]

This is what I use to access the files

directorypath=sprintf('the location of the files');

fid=fopen(directorypath);

header = fread(fid,20,'float');

fclose(fid);

Are you referring to fopen?

[Walter Roberson]

That code only reads 20 floating point numbers (single precision), which is not enough to store an image. Is there a later fopen/fread/fclose as well? Is there possibly a call to multibandread() ?

It is certainly possible to store images as pure binary files, but it is not common to do so (except perhaps temporarily as part of a process of recording them from an instrument that is producing them.)

At the moment we have to wonder how your images are being produced, and whether perhaps the artifact is already present in the data you read in.

[JayJay]

Sorry about that! You were right. The artifact is inherently present in the image. My bad. Thanks for all the help anyway!