I just start exploring computer-vision field and I'm trying to create something like this (this image is what I'm trying to achieve not what I've already achieve)
My approach is (just a logical solution, havent try it yet):
Color detection.
First, get pixel position of lines with red and green color then add all that value to arrayRed and arrayGreen.
Segmentation
Get base image from cache then get all pixel with value that close to arrayRed and label it as label background. Do the same for arrayGreen
Convert color space to RGBA and set the Alpha of label background to 0
My question :
Am I on the right path?
Is this possible to achieve with OpenCV library?
If my approach is wrong, what's the efficient and actually right approach(in pseudo-code or python) to achieve the goal?
Related
Currently, I am doing Image COLOUR filtering operation second MEDIAN filtering then CANNY EDGE DETECTION ALGORITHM.
Then, I read pixels using for loop and I draw lines using pixel, but I do not getting proper result for palm scanning and showing lines on human Palm.
So if anybody has any types of idea regarding this then please let me know.
Currently i am getting this type of result:
but I need this type of output:
Oh I got your problem, You can do this by following steps.
1.process your hand image with canny edge detection algo lets name that cannyImage.
2.now create the bitmap of cannyImage and remove black pixels from the image and replace them with transparent pixels, black only because canny image will be filled with black color and objects lines in white when you process the image through the algo, now you have extracted the image with palm lines white in color, lets name that palmLineImage.
3.now the main part is MASKING you need to mask the palmLineImage on the original image.
These three steps will give you your desire O/P.
Tools you can use GPUImage awsesome library by BradLarson for this https://github.com/BradLarson/GPUImage2
For refining the palm image from background which I'm sure you have to use in future you can use GrabCut algo
LINK - https://github.com/naver/grabcutios
and now the apple has launched Photos captured in Portrait Mode on iOS 12 contain an embedded person segmentation matte that made it easy to create creative visual effects like background replacement.
Links - https://developer.apple.com/videos/play/wwdc2019/260/ , https://developer.apple.com/videos/play/wwdc2019/225/
Looks like you need to use something like the douglas peucker algorithm - to simplify the number of data points and smooth the lines. link - https://en.wikipedia.org/wiki/Ramer%E2%80%93Douglas%E2%80%93Peucker_algorithm
Simple I have UIImageView icon with two people and it looks like this:
but when I set tintColor to red it looks like this:
Is there any way to avoid covering every non zero-alpha pixel? I need to show the tie really there. One time I need people red, other time green.
The icon is simple png file. Rounded circle is simple background color of UIImageView. So the part of the image with tie cannot be zero-alpha.
Is there any way to achieve such effect WITHOUT creating images for every color?
This was similar to another idea I had been playing around with, so I did a little more fiddling...
Starting with these 3 images:
and then using them as .withRenderingMode(.alwaysTemplate) to give the desired colors... and then layering them via CALayer to get:
and an "exploded" view for clarity...
Create an image where the "people" are 100% transparent - effectively "holes" in the image.
Set the background color of the UIImageView to be the "fill" color.
You can still mask it with a circle (CAShapeLayer, for example), if you don't want a white bounding-box as part of the image.
Original images:
https://i.stack.imgur.com/eFrmB.png
https://i.stack.imgur.com/2GNDX.png
Use the CISpotColor filter:
https://developer.apple.com/library/content/documentation/GraphicsImaging/Reference/CoreImageFilterReference/#//apple_ref/doc/filter/ci/CISpotColor
This allows you to specify a color in your image that is to be changed into another color. Thus, since you know the original color of the tie and the background, you can change either of them, or both, in a single move.
We are developing an app where we need to crop an image according to the selecting object area. User will draw a line and we need to select the object and crop it .This crop need to be like the app: YourMoji
So far we have tried to get the color of the pixels along the line and then comparing those with the color of every pixel in the image and making a path from it to clip the image. But the almost going no where.
Is it possible through this way to crop an image or we are going in the wrong way? Can anyone provide a way to do this Or suggest a way to modify the way we have worked so far? Any advice and suggestions will be greatly appreciated!
Thanks in advance.
I guess what you want is the image segmentation algorithm called Graph Cut.
Here are two Github repositories, hope these would help:
GraphCut
GrabCutIOS
I'm not exactly clued up on image manipulation, but the first algorithm that comes to mind is something like this:
Take the average of the pixels in the line (as you have)
Since you appear to want faces, you might want to weight reds and blues over green. Not much green in faces of any skin tone.
For each pixel, if the colour is within a given threshold outside of your selected average, remove it / make transparent.
Perhaps the closer to the original line (or centroid), the less strict the threshold becomes.
I'd then provide the user with some tools for:
Sensitivity: how large the threshold is
Eraser: to remove parts of the image that your algorithm missed
Paintbrush: to replace parts of the image that your algorithm incorrectly removed.
I am using 4-Way floodfill algorithm.
I have a transparent image with black out line.
That is staring point image(without color).
And after filling the color in this image it look like this
Please help me and let me know what can i do for proper fill.
I used and implemented myself FloodFill in other projects and the algorithm goes trough the whole draw, looking for closed spaces and then draw inside (or outside) them.
Your problem happens with every tool in the world that fills a draw, and the problem is the same, the spaces are not 100% closed.
The floodfill algorithm goes pixel by pixel and when it detect a black pixel, it stops. For example, the arm of the scuba driver is not thick enough or it has holes on it, and the flood fill algorithm manages to go trough it and not detect it as an empty space.
Nobody here can tell you why unless we take your project and analyse it, so the best I can offer is a guideline about where your error could be.
I tried the code with an image that has a very precise defined border around it (from here) and it seems to work OK with that image. I suggest perhaps that if you zoom into your image that there is some grey aliasing around the edges which won't get filled. Perhaps the algorithm has a threshold function that can be tweaked?
Try setting the andTolerance value (I tried 4 which seemed to improve my example).
//Call function to flood fill and get new image with filled color
UIImage *image1 = [self.image floodFillFromPoint:tpoint withColor:newcolor andTolerance:4];
I have a project to customize clothes ,let say a t-shirt, that have following features:
change colors.
add few lines of text ( <= 4) and change the font from a list.
add image or photo to the t-shirt.
rotate the t-shirt to custom back side.
rotate the image and zoom in/out.
save the result as a project locally and send it to a webservice ( i think to use NSDictionary/json ).
save as an image.
so my question is :
Should I use multiples images to simulate colors changes. Or should I use QuartzCore ( I am not an expert in QuartzCore but if I have to use it I'll learn). Or is there a better approach for this ?
Thank you.
The simple way to do this is to render the T-Shirt image into a CGContext, then walk the rows and columns and change pixels showing a "strong" primary color to the desired tint. You would take a photo of a person wearing a bright red (or other primary color) t-shirt, then in your code only change pixels where the red color has a high luminance and saturation (i.e. the "r" value is over some threshold and the b and g components are low).
The modified image is then going to look a bit flat, as when you change the pixels to one value (the new tint) there will be no variation in luminance. To make this more realistic, you would want to make each pixel have the same luminance as it did before. You can do this by converting back and forth from RGB to a color space like HCL. Apple has a great doc on color (in the Mac section) that explains color spaces (google 'site:developer.apple.com "Color Spaces"')
To reach your goal, you will have to tackle these technologies:
create a CGContext and render an image into it using Quartz
figure out how to read each pixel (pixels can have alpha and different orderings)
figure out a good way to identify the proper pixels (test by making these black or white)
for each pixel you want to change, convert the RGB to HCL to get its luminance
replace the pixel with a pixel of a different Color and Hue but the same Luminence
use the CGContext to make a new image
If all this seems to difficult then you'll have to have different images for every color you want.