I have a 3D image and need a method by which be able to compress it. The quality for the available methods for 2D compressing is very good. But, I could not find any suitable method for 3D. Anyone can help me about it? I am using MATLAB for my work. Thanks in advance for your help and suggestion.
You can consider that your 3D image is a video (the third dimension is the time).
Then, you can use standard video compression algorithms.
In matlab, you can use the videoWriter class to make compressed video files:
https://www.mathworks.com/help/matlab/ref/videowriterclass.html
If your data is grid based like a 2d image, you will find that it is very easy to adapt the png format to a third dimension.
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I am working on an image processing application, that uses pixel data to recognise digits in an image. I am thinking of an alternate approach wherein I convert the raster image to vector and then use the vector image. I am not familiar with vector graphics at all, and hence new to this, but just wondering the possibilities. Does anyone have any advice on this topic, or could direct me to some resources with similar approach ?
Also, could anybody tell me how does the conversion of a raster image to a vector image work, or provide me with related links ?
I am wondering there must be a way to get a depth of image. Certainly some portions can be extruded so that we get 3d version of 2d image. Any sources that will help in this out.
FYI: I would like to get point cloud from 2d image.
Thank you in advance..
Reconstruction from single 2D image is not possible. As mentioned by others, there is loads of literature to refer to. Multi-View Geometry by Hartely and Zisserman can be a good start. An example tutorial to start with: Reconstruction. you can also refer to computer vision toolbox from matlab/opencv
It is possible to draw some 3D information from a 2D image.
There are methods to extract depth infortmation from the blur of a pixel. When a picture is captured, you focus in one place and let remaining portion blur, and hence blur captures depth.
See Make3d project to startwith.
Thank you.
If I resize an image in MATLAB, what effect will that have on the original image. Say for instance I have an image of size 437x167 and I want to resize it to 256x256. Will there be any details that will go missing from such operation?
Thanks.
if i understand you correctly you mean: "what are the results on an image after using matlab's built in function imresize?" by looking at the documentation of imresize you can see that you can choose what algorithm you want to use through the parameters of imresize. the best answer can be found by googeling the respective algorithms and reading what is the data loss caused by each of these algorithms
I have an wavelet compressed image, but not sure what parameter its using for compression, is there a way to un-compress this image?. I tried using a jpeg-2000 image viewer but it did not help.
As per my understanding one should know the wavelet on which it was compressed to proceed further, but this information is missing at present. Does this mean the images remain encrypted and cant be decoded?
Do you know the data format? if you plot it can you see the main bands and sub bands at the various levels of detail?
Once you have the data format, you can simply try a few possible wavelet shapes, starting with the Haar for simplicity. At least you will get a good impression of the image content.
If you don't know the data format, you are probably stuffed.
Given an photograph uploaded by a user, what is best approach to creating a number various sized thumbnails Using ImageMagick (or GraphicsMagick)? My guess to the steps:
Create a super sample of the image, maintaining original aspect ratio
Apply watermark to super sample
Create the various sized thumbnails using the watermarked super sampled image
Additional requirements:
Best quality possible (does this mean PNG over JPG?)
Smallest file size possible (does this mean JPG over PNG?)
Use density of 72x72, units is ppi
Since I am not that familiar with the intricacies of IM (or GM), some guidance to the best commands that meet my objectives would be highly appreciated. Thanks.
Check out the ImageMagick documentation:
For a specific size http://www.imagemagick.org/Usage/thumbnails/#fit
For watermarks http://www.imagemagick.org/Usage/annotating/#watermarking
The best quality possible is complicated since difference images compress differently. I'm partial to PNG since it has a variety if compression techniques available to allow for experimentation.