I want to make a program where I have an image and I display it to the user, and the user then crops out the unimportant part, while matlab waits for him to finish. Then the rest of the program is run where the image processing is done on the part of the image that is left.
I found the 'waitfor' function but I am not sure how it is to used in this case. Also will the corresponding matrix be updated with the values of the cropped image?
I think that you need imcrop
It's a matlab tool to crop images. You draw the rectangles, and then you can move it. You double-click to finish.
Related
I don't know why, but Matlab Camera Calibration app is getting also the peripheral corners, it is not supposed to do that. Any clues?
By the way, the border squares are more thinner by purpose, just to try to make Matlab ignore them, I also used normal squares side on the borders but I got the same Matlab behavior.
My image result:
Correct result from matlab website:
The thing is that Matlab usually can't handle a "perfect" image. Since I was analyzing my patter before printing and not an actual photo of it, it seems the corner detection get lost. I just added some blur to my pattern and Matlab was able to detect it correctly. Another "solution" is to reduce the borders size, since there is no need to them to have the full rectangle size.
Perfect image
Perfect image + blur - OK
Perfect image with 40% borders - OK
Original perfect image with 40% borders
I want show large image in Matlab gui, but when show my image not clearly and not possible for read. for example show my image in Matlab in follow.
Any way show my image like this image?
I know can use zoom in and zoom out, but image in first should clearly.
You can use InitialMagnification to preview the image at your native resolution. If your concern is getting a nice looking zoomed-out image, you can try using reduce parameter of imshow to sub sample it.
I loaded several PNG files into Matlab and displayed them with no problem but was wondering if there is a way to point (or click) on a pixel and immediately get its pixel coordinates and color (RGB), in real time, either as an output on-screen or stored in some variable.
For example, I have a 64 x 64 face photo to serve as a ground truth image for an eye detection algorithm. The algorithm will return the bounding box for an eye, but, to check it, I want to manually extract coordinates by clicking or mousing around the image as it is plotted, and also color information about the pixels on which I click or mouse.
Please feel free to suggest another language, software, or environment if Matlab does not support such interactivity.
Thank you for your help!
The Data Cursor does exactly what you want:
http://www.mathworks.co.uk/help/matlab/creating_plots/data-cursor-displaying-data-values-interactively.html
It is the icon to the right of the "rotate" icon in the image toolbar.
If you have the Image Processing Toolbox, there is a built in tool called impixel, which will allow you to click on an image and get pixel values and location automatically. There is no data cursor that pops up, but what the data cursor is returning, impixel is also, and you could easily display this with a uicontrol (text).
I am new for iOS Development . After googling I found that, it is easy to blur whole image but it is difficult to blur specific part of image such like rectangular or circular. So please help me how can I blur specific part of image rather then whole image ?
Thanks in advance.
Blur the whole image, then crop to the part you care about. You can use a mask for non-rectangular/non-sharp-edged blurs, but don't skip the crop.
The lovely, but sometimes tricky, thing about
Core Image is that it's extremely lazy. It doesn't work from the start to the end; it's more of a pull model, working from the last thing you asked for all the way back to the original rasters. Moreover, it won't actually filter any pixels you have not asked for.
So, in your case, a crop means not asking for any blurred pixels outside of the crop. Since you didn't ask for them, they don't get blurred. The blur only runs on the pixels you ask for—the ones inside the crop.
Masking works differently; by definition, it needs to look at every pixel in the mask image, and I would be surprised if it didn't also look at every pixel in the source (even to multiply it by zero). This is why you should still crop, even with a mask.
Note that the blurred-and-cropped portion of the image will still be where it is in the original image. It doesn't copy/move the pixels within the image, because that would be expensive; instead, it returns an image with a different extent—namely, the crop rectangle. You'll want to retrieve that extent and subtract its origin from the coordinates where you want to draw the image—either that or use an affine transform filter, but, again, that would probably be expensive.
I'm the beginner of image processing by using MATLAB and i have to do some tasks, i want to crop or cut for the specific area like using imcrop but want to make it automatic (i cannot upload picture because i'm the new user, the picture that i use is the cross-section of a plant) i really don't know how to detect and cut out only that area. I'll really appreciate if there's someone can help me to figure out this problem.
You need to give us more information. If you want to automate the detection of a part of an image to crop it, you need to do some image processing. What kind will depend on the characteristics of your images and the part you want to crop.
You can post an image using, for example, http://www.postimage.org/