i have developed an android app for color comparison. and i ve successfully completed the app except solving one problem that is illumination problem. my reference chart is in sdcard as jpeg images I need to compare those images with the images which i takes from camera. i am getting the output but it depends the illuminity. so now i am planing no normalize the bit maps. How to normalize a bitmap.?? i am comparing images using naive similarity method
and please suggest me one good idea to solve the illumination problem. searching metheds sonce last two weeks .
Try to use Catalano Framework. Here contains the article that you can learn how to use.
I implemented Image Normalization using this approach.
FastBitmap fb = new FastBitmap("image.jpg");
fb.toGrayscale();
ImageNormalization in = new ImageNormalization();
in.applyInPlace(fb);
here is a link asking a similar question about luminosity, so I won't repeat everything.
Color is perceptual, not an absolute. Take a red car and park it under a street light and the car will appear to be orange. Obviously the color of the paint has not changed, only your perception of the color has changed.
Any time you take a photo of color, the light used to illuminate the image will change the results you get. Most cameras have a light balance control, where most people use auto. The auto control looks something to call white, then shifts the image to make the white look white. This does not mean the rest of the colors will be correct.
Take something like a colorful stuffed animal (or a few) and take its photo outside in sunlight, under an incandescent bulb, under florescent light and in a dark room with the camera flash. How similar are the colors? If you have photoshop, look at the color curves in photoshop.
To match color, you need an objective standard, such as a color card included in the photo. Then the software brightness and color correct the known card, then measure the other color to the known standards.
Related
I have two images - background & foreground, having different lighting conditions and colour tones. Each of them contains a person. Also i have an alpha mask for the person in foreground image. I want to blend the person (cropped out using mask) from the foreground with the background image so that the final image looks as if the person in the foreground was standing next to person in background(i.e realistic composite blending).I already have the segmentation mask and i'am able to get the cropped out person from foreground image.It looks like we need to ensure proper illumination, saturation and colour matching to obtain a natural blended feel.It seems, we can easily do that using photoshop manually(link1,link2). How can achieve similar results programmatically, given two random background and foreground images with person?
The following are the approaches i tried; but each of them have certain issues and works only with certain types of images.
1.OpenCV Seamless clone - Works pretty well for plane and similar contrast images.Issues:- heavy, smudging, cannot be generalised for all types of images.
2.Photorealistic style transfer - Works great; but its heavy, needs special training and works only with few class of images. Still artefacts may be present.
3.Fast Color Transfer (pyimagesearch)- Works for plane background. Background color averaging causes colours to be spill over to image roi and thus loses its natural feel.
Also tried normal alpha blending, laplacian blending, histogram matching etc. Additionally, experimented with techniques like CLAHE, gamma correction, histogram equalisation, edge blending etc to adjust and improve the output of blending. Unfortunately, none of these combinations gave the desired result.(NB:-The output should not ideally look as if a layer is stacked or pasted on top of background image).i.e we need a seamless natural blend.
Is this possible only using some AI models or is there any light weight methods for performing automatic image composting in java, using some standard libraries (should work adaptively for any two images in general)?
We are trying to achieve something similar to the following methods:-
https://people.csail.mit.edu/yichangshih/portrait_web/
https://arxiv.org/abs/1709.09828
https://www.cs.cornell.edu/~kb/publications/egsr18_harmonization.pdf
Finally found the answer..Here is the caffe implementaion of Deep Color Harmoniation: https://github.com/wasidennis/DeepHarmonization. It seems to a light weight network and works pretty fast. Still trying to figure out how to convert the same to a mobile friendly format like tensorflow lite ...
Hope it helps somebody ...
For reference the effect I'm going for is this:
I'm working in Processing 3, NOT p5.js.
I've looked around processing forums, but i can't find anything that works in the current version or doesn't use PGraphics and a mask which from what I've read can be expensive to use.
My current ideas and implementations have resulted to drawing shapes around the player and filling the gaps in with a circles with no fill that has a large stroke weight.
Does anyone know of any methods to easily and inexpensively draw a black background over everything except a small circular area?
If this is the wrong place to ask this question just send me on my way I guess, but please be nice. Thank you:)
You could create an image (or PGraphics) that consists of mostly black, with a transparent circle in it. This is called image masking or alpha compositing. Doing a Google image search for "alpha composite" returns a bunch of the images I'm talking about.
Anyway, after you have the image, it's just a matter of drawing it on top of your scene wherever the player is. You might also use the PImage#mask() function. More info can be found in the reference.
I tried to gets the prominent color of an image using this example. This is working perfect for plain images. But when I'm giving an image like this,
It's give me the color RGB(0,4,7)(a black one). How may I fix this?
In fact you are not looking for the dominant color, but more for the dominant range of color. So you are looking for the bigger cluster in the RGB histogram. Take a look to the papers of Arnaud LeTrotter (at this time he was working at the LSIS laboratory in Marseille, France), it's exactly what he did. He added some tolerance to the main color detection in order to have the main range.
I'm quite new to LibGDX and OpenGL, but I managed to make a simple liquid simulation using Box2D API. See this link (this is someone's else animation):
Physics Liquid
Currently I render the liquid particles as circles just like in the first image, but I want to make it look more natural like on the third one.
The answer might be to use distance field and I tried this approach, but with no effect. I'm drawing each particle as a texture using SpriteBatch class, but that can be changed. I made a texture (from a procedural Pixmap) that represents each particle as a filled circle, with alpha channel decreasing further from the center, so the effect is similar to the second picture.
Now, I must enable a threshold filter to alpha channel, something like: "draw only pixels with alpha > 0.5". This is post-processing step, because it matters what is the alpha channel of a pixel after all particles have been draw. Might or might not be done with shaders (ProgramShader), but after some research I still have no clue how to do this. Thanks for ANY help.
EDIT: this example explains the method, but it's implemented in ActionScript.
This can easily be done using shaders, but funny thing is that you don't need to write them.
"draw only pixels with alpha > 0.5" is also used while rendering distance field fonts (fonts which look good even when scaled up).
Follow this link : https://github.com/libgdx/libgdx/wiki/Distance-field-fonts
Directly jump to the last step.
You should find exactly what you want.
Hope this helps.
I have two pixel arrays, foreground and lighting. When I draw a white radial gradient (blurry circle) onto the lighting array, I want it to make the foreground visible - much like a torch in terraria/starbound. However, I also want to be able to mix different colors of lighting, rather than be stuck with black to white.
So how do I manipulate the pixel arrays so that they 'multiply' (I believe it's called)? Or is there an easier way using RGBA which I have not been able to get to work (flickering black on white or image getting ever more posterized)?
So far most responses regarding alpha channels / opacity have been using libraries from java which for this project I want to refrain from using.
Any help much appreciated!
If you want to know how the blending modes (such as "multiply") work in image editing programs on the pixel-value level, read this: How does photoshop blend two images together?.
Note that if you want to make the image lighter, you need a mode like "screen", because "multiply" makes it darker.