hye everyone i m doing my project "automatic vechicle identification".i have to design software in matlab,i have done extraction of plate region ,segmentation of characters,...now i want to save these segmented characters so that i can further recognize these character from a data base......any body can help me please feel free to write to me, thanks in advance
So if you have some data, myData then you can just issue a command save myData and you will have a new file in the current directory named myData.mat. To load the data later, just type in load myData and then you will have a new variable in the workspace named myData. There's lots more you can do with this, so you should check out help save.
Alternatively you could use a database. I've never actually used a database in Matlab, but there seems to be plenty of information about how one would go about doing this: http://www.mathworks.com/help/toolbox/database/ug/database.html
Related
I try to add a thumbnail to a JPEG picture using libexif.
For now I'm borrowing the code from exif (the command line tool that is shipped by the libexif team).
However I noticed the XMP tags get deleted from the metadata. There is an old bugreport here.
I tried to see how to achieve this anyway with libexif but I don't really understand how to get the XMP from input file and put it in the output file. I just want to copy all XMP data, I don't need to extract anything of it.
I saw there is a TAG EXIF_TAG_XML_PACKET in exif_tag.h but couldn't figure out how to read/write this tag.
A related solution is in this SO answer but it looks complicated. I'm not familiar coding in C.
Is it actually possible to keep all XMP when using only libexif API? Have things changed in recent years on that? How would you write this in code?
Thanks
I believe it should be somewhat straightforward. XMP fields are described in the ISO/Adobe standard. Regular Kotlin/Java/Android file I/O and some string manipulation should be all that is required.
I would start out by becoming intimately familiar with ISO 16684-1:2019. Then, write a method for your jpeg file class that grabs all the XMP fields. Store those fields in a temp file (to prevent difficult to recover data loss in the event of your code or libexif crashing). Hand the file off to libexif. Generate the thumbnail. Finally, when that's done you can restore the XMP fields. If the thumbnail is stored in an XMP field as well (and it sounds like it is), it may be easier to concatenate that field with the other ones which were already grabbed, updating the temp file so that it contains EVERY XMP field, before adding all of the XMP fields back to the jpeg.
Unfortunately, I do not currently have the time to read a 50 page ISO standard, synthesize the information, and then write the code to implement the solution. Here's a link to the standard at least, to get you started.
https://www.iso.org/obp/ui/#iso:std:iso:16684:-1:ed-2:v1:en
I am working on an experiment that take a lot of data samples and save it to different video files. For example, I take data and save it to a file called "slowmotion.avi" and then I take another set of data and save it to another file called "normalspeed.avi".
I am trying to find a way that I could change the name of file being saved without editing the code. The way I am using right now makes me have to open the code and change the name of the file directory within the code and then save the code. I want to make it a lot faster and easier to use.
I have tried the following code to fix this problem but it doesn't work.
graph=input('Graph of experiment: ');
vidObj = VideoWriter('%3.1f.avi\n',graph);
.....
Hope I didn't confuse you.
A possible solution:
graph=input('Graph of experiment: ','s');
vidObj = VideoWriter([graph,'.avi']);
The 's' in the input() function indicates that the expected input is a string, and [graph,'.avi'] simply concatenates both strings.
I have a dicom from a GE MRI scanner and there are a few pieces of information in the header I require (namely the relative position of the scan). I tried using info = dicominfo(filename) but, for some reason, this piece of information does not show up. I know that this information is saved, however. It might be a private data, but I'm not completely sure. If anyone has any information on how to resolve this issue that would be greatly appreciated.
Try using the dicomread function instead, it should be more versatile than dicominfo and it reads the information files too. If this doesn't work then it means that the information you are trying to obtain is not made available by GE.
Or use gdcm to dump the private GE header:
$ gdcmdump --pdb input.dcm
I am going through someone's data analysis files (created in an older version of matlab) and trying to find out what a particular .mat file is that was used in a matlab script.
I am trying to load a .mat file in matlab. I want to see what is in it.
When I type...
load ('file.mat')
the file loads and I see two variables appear in the workspace. jobhelp and jobs.
When I try to open jobs by typing the following in the matlab command window...
jobs
the response is..
jobs =
[1x1 struct]
Does this mean that there is only a 1 x 1 structure in the .mat file? If so, how in the world do I see what it is? I'm even happy to load it in unix, but I don't know how to do that either. Any help would be greatly appreciated as I have a few files like this that I can't get any information from.
Again, a new user, so please make it simple.
Thanks
It means that jobs is a cell array {} and within this cell array is a structure defined
To see the structure and its contents type jobs{1}
I think you are dealing with a SPM5 Batch-File. This variable is an image of the tree-like structure you can see in the Batch-Editor of SPM. Your job consists of one subitem (stats) which could have various subsubitems (like fMRI model specification, model estimation and so on).
To access this structure on the command line just proceed like Nick said:
Each level is a separate cell array that you can access with {#} after the name of the level. Example: jobs{1} shows you that there is a subitem named stats.
Subitems in structs are accessed with a dot. Example: jobes{1}.stats{1} shows you the subitems of the stats-entry.
Notice that there could be more than one entry on each layer: A stats module could (and probably would) contain various subitems. You can access them via jobs{1}.stat{2}, jobs{1}.stats{3} and so on.
The last layer would be the interesting one for you: The structures in here is an image of the options you can choose in the batch-editor.
Many photo viewing and editing applications allow you to examine and change EXIF and IPTC data in JPEG and other image files. For example, I can see things like shutter speed, aperture and orientation in the picture files that come off my Canon A430. There are many, many name/value pairs in all this metadata. But...
What do I do if I want to store some data that doesn't have a build-in field name. Let's say I'm photographing an athletics competition and I want to tag every photo with the competitor's bib number. Can I create a "bib_number" field and assign it a values of "0001", "5478", "8124" etc, and then search for all photos with bib_number="5478"?
I've spent a few hours searching and the best I can come up with is to put this custom information in the "keywords" field but this isn't quite what I'm after. With this socution I'd have to craft a query like "keywords contains bib_number_5478" whereas what I want it "bib_number is 5478".
So do the EXIF and/or IPTC standards allow addtional user-defined field names?
Thanks
Kev
It can be used for that, but it really shouldn't: it's meant to be user-editable and so isn't a safe place to put critical metadata. Using an XMP sidecar is better for this kind of thing: in XMP, any field added that a given app does not understand is, according to the standard, supposed to be ignored by that app and not destroyed.
I don't know if there are applications to do this but by the standards described for JPEG files there is a field called Comments where you can assign values that could act like tags.
C# code:
using System.Windows.Media.Imaging;
using System.IO;
...
FileStream fs = new FileStream(#"<img_path>", FileMode.Open, FileAccess.ReadWrite);
BitmapMetadata bmd = (BitmapMetadata)BitmapFrame.Create(fs).Metadata;
bmd.Comment = "Some Comment Here";
also if you are looking for an application that already has this functionality built into it, then might i recommend Irfan View (open pic, go to Image menu, click on Comments button).
Hope this helps.