# Questions tagged [algorithms]

step by step procedure to calculate a value

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### Do any cameras have advanced auto-exposure algorithms?

Reading answers to Why are my sky photographs coming out dark?, I began to wonder: are all current autoexposure algorithms really so basic as to just measure the average brightness of the scene? It ...
204 views

### How do cameras convert colorful noise to colorless?

Modern phones have some amazing processing of the data from their cameras. For example, the raw image below of a sculpture in a park after sunset (demosaiced using IGV method in RawTherapee and ...
119 views

### Is it possible to combine several manually taken photographs of a still presentation slide into an image of a better quality?

I often go to presentations and take photos of slides. Sometimes I sit too far, and photos come out blurred or noisy. It is known that if to take N photographs of the same object from exactly the ...
89 views

### How does the camera meter in auto mode when you are not taking a photo?

Typically, when you are in auto mode, if you half-press the shutter, the camera meters. But, even when you don't do that, the camera seems to be continously metering, so you get a pretty accurate ...
100 views

### What is the best way to downsample photos to increase sharpness [duplicate]

What is the best way to downsample photos to increase sharpness? If I have a photo in raw format with a resolution of about 24MP. How do I best downsample it to increase sharpness if I think the ...
139 views

### Why Is There No Reference White Balance

I understand why White Balance is a necessary part of any imaging pipeline, but I don't understand why using a colorchecker on a measured sensor does not have an associated reference equation to ...
112 views

### Enlarge an image without contour having a staircase effect [closed]

I know it's impossible to magically "add more resolution" to a 600x600px image to turn it into a 3000x3000px image (goal: print it in around 30x30 cm). (I have done some signal digital processing math,...
126 views

### Has anyone reverse engineered and published common in-camera adjustments by major manufacturers?

Most cameras offer various in-camera adjustments to produce jpeg output. For example, Olympus has an adjustment to adjust saturation: In theory, one could compare the raw file with the resultant ...
364 views

### What demosaic algorithm is best for DNG to B&W conversion?

I figure that at some point someone has devised a demosaic algorithm that is optimal for converting a Bayer DNG to a B&W photograph. But what is that algorithm called, and what image processing ...
1k views

### How to calculate distance of an object from camera or size of an object in an image? Have to utilise already generated camera parameters to find these [duplicate]

How to calculate distance of an object from camera or calculate the size of a object in an image? Given that, I have already generated the camera parameters (intrinsic and extrinsic). I have to ...
1k views

### Options to double image dimensions of artwork photo? [duplicate]

I have some high-quality RAW files of artwork that I've processed with some cropping, contrast adjustment, etc. I'd like them to be printed on metal at about 2'x3', which is about twice the size I get ...
143 views

### In working out Auto White Balance, what to do if there are multiple sources of light?

I'm trying to research Auto White Balance Algorithms. These algorithms are defined assuming only one source of light. For example: 1.Grey world assumption ( this assumes that R, G and B average ...
2k views

### What algorithm can I use to simulate bokeh?

I am attempting to write a script that loops through each pixel in a photograph and applies a bokeh to the image as a whole. I built a script based off this link, however that seems to be a hack. I ...
209 views

### algorithm deflickering timelapse shots?

before you ask yes I already saw this subject(What algorithm can be used for deflickering timelapse shots?) The answer of Matt Grum is nearly what I'm looking for but I need more precision and I ...
2k views

### How does 18% exposure algorithm work?

They all say and teach the rule that camera exposes to 18% grey. Then they go and show an example of shooting a white board or black board and they both show as a grey board in the camera. Great, but ...
3k views

### Would a demosaic algorithm for black and white be useful?

Given that the main purpose of demosaicing is to recover colour as accurately as possible, would there be any advantage to a "black and white only" demosaic algorithm? That is, instead of first ...
2k views

### What algorithm can be used for deflickering timelapse shots?

What are deflicker algorithms used to deflicker stills that should be composed to a timelapse movie? (Flickering caused by shutterspeed adjustments in sunset/sunrise shots...)
4k views

### How does “smile shot” work in cameras?

Nowadays some advanced cameras have the feature of "smile shot" without the photographer pressing the shutter. How do the cameras achieve this? How does it recognise the smile?
516 views

### Does the curves tool in Photoshop (or any software) do anti-aliasing?

I'm not talking about drawing smooth curves here, but rather the curves tool used for adjusting color levels. An illustration will be worth a thousand words, here. This is an adjustment in Gimp: ...
479 views

### How to understand the definition of dynamic range?

I have the following formula: DR=(1.4L_Sat G_i)/N_D where DR is the dynamic range; L_sat is the luminance at the “margin level”，70.1% of the maximum recordable （saturation）luminance（yes，L_sat is ...
325 views

### some criteria when a filter looks good

I'm a developer who wants to figure out when a filter would look good applied to a given image. For example, I have sepia, solarisation and pencil filters. Okay, the perception will be very ...
218 views

### Learning about photography algorithms [closed]

I'm very interested in learning about algorithms in photography (in particular processing photos). In addition to algorithms, I'm interested in learning about photo formats (probably RAW and jpeg the ...