I am new at image processing and am working with pixel values.
I just learned image pixel brightness now I want to learn contrast.
I searched the Internet but my brain is not getting it.
I'd like to know if you know some thing that could help?
What is concept of contrast?
What is it's effect on each pixel of image?
Related
We have color images as reference images and they do work great, but the problem we are facing is as following, what we have is a coloring book for children, a sample image from the book is like below
1.This is what a physical Reference Image will look like
Now coming to our use case, as i mentioned this is a coloringbook for children, so I tried to create a worst case(use as many colors as possible and color as much of the white space as possible) scenario image which looks like this
2.Worst case physical image can be
Now the issue is with the point 2, the arkit is not able to the image at all, I assume because I have used enough colors that now arkit looks at it as different image compared to the given referenceImage.
Is there any way I can detect the worst case of the image also, may be by using monochrome(black and white) images? please suggest
If I have understand well, 3D 360 photos are created from a panorama photo, so I guess it should be possible to create a 3D photo (non 360) from a normal photo. But how? I did not find anything in Google! Any idea of what should I search??
So far, if nothing available (I don't think so), I'll try to duplicate the same photo in each eye. One of the pictures a little bit moved to the right, and the other one moved a little bit to the left. But I think the distortion algorithm is much more complicated.
Note: I'm also receiving answers here: https://plus.google.com/u/0/115463690952639951338/posts/4KdqFcqUTT9
I am in no way certain of this, but my intuition on how 3D 360 images are created in GoogleVR is this:
As you take a panorama image, it actually takes a series of images. As you turn the phone around, the perspective changes slightly with each image, not only by angle, but also offset (except in the unlikely event you spin the phone around its own axis). When it stitches together the final image, it creates one image for each eye, picking suitable images from the series so that it creates a 3D effect when viewed together. The same "area" of the image for each eye comes from a different source image.
You can't do anything similar with a single image. It's the multitude of images produced, each with a different perspective coming from the turning of the phone, that enables the algorithm to create a 3D image.
2D lacks a dimension hence cannot be converted to 3D just like that, but there are clever ways for example Google Pixel even though doesn't have 2 camera can make it seem like the image is 3D by applying some Machine learning algorithm that create the effect of perspective and depth by selective blurring.
3d photos can't be taken by normal but you can take 360 photos with normal camera ..... There are many apps via which you can do this ..... Also there are many algorithms to do it programmatically
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 trying to play around with turning an image into mosaic bricks like the Lego Photo app.
How is it done, and where can I find more info?
You basically need to iterate through the pixels, to calculate the average colour for say every 4x4 block of pixels. Once you have this average colour, you 'round' it to the nearest colour that you can use in your mosaic. I don't know the specifics of it but this sample code does exactly what you want.
I am in a situation in which I need to display particular pixels of an Image in an ImageView.
Is there any way to do this in iPhone?Can anybody provide some Example code to do this?Please help me to solve this problem.
There are many ways to display a small subset of your pixels. You can get the raw pixels with this.
Or you can crop a photo. Or you can mask a photo so you are left with just a small bit of your image.
What exactly do you mean by "display particular pixels"?