Questions tagged [image-processing]
Image processing is the computational transformation of an image signal. It's about the technical side of batch transformations, conversions, and enhancements, as distinct from post-processing (adjusting an image to achieve a desired look, probably using image processing).
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What does an unprocessed RAW file look like?
I know people use fancy software like Lightroom or Darktable to post-process their RAW files. But what if I don't? What does the file look like, just, y'know, RAW?
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What tools are available for RAW image processing in Linux?
I have been taking photographs with RAW format.
What tools are available for working with RAW under Linux?
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What does "frequency" mean in an image?
I don't understand how frequencies are defined in images/photographs. As far as I understand it now, high frequencies are like sharp things in images, like edges or so, and low frequencies are kind of ...
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How can I tell exactly what changed between two images?
For example, for a recent conversation about JPEG compression I wanted to compare pixel for pixel what changed between two JPEGs (one with compression level 100, and one with compression level 95).
...
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How was photo data processed and transferred back to Earth from satellites before digital photography became commonplace?
I am looking at pictures taken by some of the first satellites and landers there were like the Viking Lander on Mars in ~1976 or even the first image of the backside of the Moon in 1959 by Luna 3
I ...
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What are Color Profiles and where would I find information on using them properly?
I see the term "Color Profile" a lot and I have this vague idea that it helps you adjust color values based on the unique differences of both cameras, displays and printers from some ideal device. ...
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How does exposure fusion work?
I understand that "exposure fusion" is a method for combining different exposures into a single image. How exactly does it work, and how is it related to HDR?
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Where can I get free RAW files online for practicing with Lightroom?
I've downloaded Adobe Lightroom in order to learn RAW image processing. I want to practise on some photos that covers basic subjects (Histograms, HDR etc).
Is there a good, free source of RAW images ...
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Can software auto-detect image focus?
I was wondering if there was any photo management software out there that could auto detect and "rate" images on how in focus they are.
This comes up for me quite commonly when i am looking through a ...
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Other than the iMac, what's a brilliant display for my images?
When I started researching gear to start my photography passion I fell in love with the large iMac display. The large bright screen at the best buy was showing a sideshow if images that looked better ...
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How to auto-align a stack of head shots?
I am working on my own "everyday face" project - taking pictures of myself to combine them in a sequence afterwards.
I'm wondering what is the easiest and fastest way to align all pictures so my ...
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How can I convert an Apple iOS HEIF image into JPEG?
How can I convert an HEIF/HEIC image into a JPEG? Maybe using ImageMagick?
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Is it possible to make a single still photo from a video?
The idea comes from the fact that in astronomy (amatorial), it's common to take videos from a telescope with a webcam and convert them into a single, less noisy picture.
The principle is that of ...
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Cheap/free tool to view/convert Canon CR2 RAW format photo files on Windows?
Recently, my family had some professional photos taken while vacationing at a resort. The photos were given to us on CD in both .CR2 and .jpg formats.
While we can view the JPEG-format versions of ...
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Is it possible to find out what compression ratio was used for a particular JPEG?
I have a couple of JPEGs. Is there a way to find out which compression level was used when encoding them? That is, were they encoded at level 60 or 90?
The reason I'm asking is because I have a site ...
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Nikon RAW image processing in non-Nikon software
I love Adobe Lightroom, the workflow, the interface, the whole package. However, as a Nikon owner never did I manage to get the colors to look as good as after processing with Capture NX. No doubt ...
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Is it possible to print a photo so it can be mounted on a globe?
I'd like to transform an image so that it can be mounted on a sphere. I'd like to use an image of a map (see the One Piece world map on the image), but it could be anything. Here is a kind of Family ...
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How to analyze images with Fast Fourier Transform method?
I am learning about analyzing images with the method of FFT(Fast Fourier Transform). The image I am analyzing is attached below:
Portrait of woman posing on grass, by George Marks. Getty Images.
And ...
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What noise removal tools work best, and why?
Can anyone recommend some good noise removal tools, free and commercial? Should support RAW and JPEG. Are certain tools better than others in particular situations? Do some integrate better with other ...
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Why don't cameras record light data throughout the entire shutter?
Sorry if the question title is confusing, I don't know the best way to word this,so feel free to change it if you can think of something better. I learned electronic shutters can capture the image all ...
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Is post processing always necessary for best results?
While using my old Point and Shoot camera I used to think about post-processing photos in Photoshop like something unnatural, fake, and deceptive. But after buying DSLR I have not only to think about ...
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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 ...
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How would I go about using my SLR to measure the 'greenness' of a photo?
Background
My digital pictures can be read into a computer program like Matlab or R as a m x n x 3 matrix where m x n is the number of pixels observed by each of the three (red, green, and blue) ...
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Can I combine several low quality pics into one higher quality picture?
Is there an easy tool to combine low quality pics taken from a mobile phone, all of the same thing but taken within a few seconds interval from one another, mostly suffering from slight out of focus ...
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Why is a physical anti-aliasing filter still needed on modern DSLRs?
I understand the purpose of the anti-aliasing (AA) filter is to prevent moire. When digital cameras first emerged an AA filter was necessary to creat enough blur to prevent moire patterns. At that ...
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What would happen if a camera used entirely different primary colors?
So, as many people know, humans have three cones cells, enabling us to see three distinct "primary" colors, which may combine to form the entire spectrum that we are capable of seeing. Meanwhile, many ...
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What is the difference between HSV and CIE-Lab color space?
When do we (or should we) use HSV color space and when do we use CIE-Lab color space?
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Why does my Canon 700D take so long processing when I take a long exposure? [duplicate]
I am trying to get into long exposure time lapse photography, and was wondering if there was a way of speeding up or turning off the processing of the image! When doing long exposure time lapse at (...
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What are the merits of using a particular image file format?
If I edit an image file using some application like GIMP, Photoshop or MS Paint, while saving I will be asked to select the required file-format. There are different formats available, the common ones ...
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How can I "focus peak" a photograph?
Does an application exist where I can input an image and then the application indicates what parts of the image are in focus? I imagine it as a sort of post-process focus peaking.
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Is it generally accepted that "Samsung 'space zoom' moon shots are fake" and that some cellphones (e.g. S20 Ultra) use AI to add features?
a comment on my answer to What is the ring of light around the moon and which star seen near it? links to the reddit Samsung "space zoom" moon shots are fake, and here is the proof.
I have ...
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How can I detect upscaled photos?
I have a collection of JPEG photos, each 500 to 600 pixels on the longest side. How can I detect which ones have been algorithmically enlarged from a substantially smaller photo?
An online ...
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Is the image processor relevant in a camera when shooting RAW?
When cameras come out the company often states that the image processor is upgraded.
Does such an upgrade matter when one only shoots in RAW?
When shooting RAW ...
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What is a quick way to restore old black and white and sepia photographs?
I have a bunch of old black and white and sepia photographs from my grandparents' album that I scanned and would like to restore. The photographs are generally in good condition. there are some ...
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What software should I use for converting fisheye photos to normal rectilinear photos?
Can you recommand me a software for doing this job? I shoot using Sigma 8mm lens and I would like to be able to obtain a normal image out of that. The camera is canon 550D.
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How can I stitch images with the same center but different peripheral content?
Looking for help in solving this problem. I want to stitch a series of images together. The easiest way to describe it is, let's say, I am walking down a long street with a repeating pattern of ...
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Is it common practice to apply identical processing effects to a batch of photos?
I'm trying to understand how photographers approach the task of multiple images that were all shot at the same environment/setting/event. Instead of opening each photo separate, and tweaking hue, ...
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How can I adjust the colour temperature of an image programmatically?
I'm wondering how to convert programmatically (i.e. with a programming language rather than an editor) from one colour temperature to another?
If, for example, I make the assumption (and it's a big ...
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How can one correct intensity flicker due to AC line frequency?
Is there a good image processing method to get rid of the horizontal stripes in the images taken under fluorescent lighting? These stripes (flicker) occur when you take pictures indoors due to the 50 ...
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Can using a high resolution sensor and downsampling compensate for a soft lens?
In this question Does super-sampling produce good results? the difference in quality between using a high and low resolution sensor of the same size and then downsampling the high resolution one gives ...
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How to batch process images retaining them as PNG in Photoshop?
I need to optimize 700 images in PNG in a batch process, but Photoshop only gives me the option to optimize the images and export them to JPG, when I want to mantain the images on PNG.
Is there a way ...
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What workflow should I use for processing RAW photos in Lightroom?
I started shooting in RAW, and I use Adobe Lightroom.
What workflow would you recommend to use for the processing?
I will really appreciate a detailed description of the steps (or a link to one).
...
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Does it matter what edge finding algorithm you use?
I was playing around with an action set that I have that creates edge masks using the Roberts, Robinson, Sobel, Prewitt, and Kirsh algorithms. Because of the differing levels of brightness, I decided ...
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Process stereoscopic image to convert from 3D to 2D
I am wondering if it is possible to take a stereoscopic image and sum them in such a way that makes it a monoscopic image, with the resulting viewpoint in the center of where the two viewpoints ...
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How much does in-camera image processing affect noise on Canon DSLRs?
I've found out that some of photos take with my 5D MkII have more shadow noise than I like. I know there are some obvious settings that affect this, such as ISO a noise reduction settings. But there ...
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Is "saturation" an image-processing concept?
Image saturation is a concept used to describe the purity or intensity of color in an image, such that an image with very little saturation approaches a black and white image. Pink, then, is said to ...
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Can deconvolution help improve the apparent sharpness of mirror lenses?
I have recently ordered a Samyang 500 mm/f6.3 mirror lens on eBay, for about £80, largely out of curiosity -- at the very least, it will be an interesting toy and I can always sell it.
Mirror lenses ...
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Object size discrepancy in image (Round object occupies more pixels than it should)
I am photographing a sphere (a ball): in the same picture I have also placed a ruler. The ball and the ruler are in the same plane. i.e. the ruler is placed such that it is aligned with the center of ...
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How to undo all changes to an edited image in RawTherapee?
My Problem
I am editing an image in RawTherapee, and I am not satisfied with the result. I want to undo all changes and start editing the original image. If possible, I would be happy to see a list ...
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