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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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1answer
139 views

Manipulating images at different spatial scales

Is there software which will allow manipulating an image at different spatial scales? For example, change the contrast or brightness of features smaller than 50 px but larger than 10 px. I have ...
4
votes
4answers
814 views

Query about gamma correction?

I have a bespoke Image Capture & processing flow, wherein I do the following operations:- Capture Raw data-->De-Bayer(Get RGB)-->Color Balance-->RGB-to-YCbCr-->Image sharpening-->Denoise ...
3
votes
3answers
591 views

Photo Processing - What am I doing wrong?

I seem to have a problem processing photos and I am not sure where I am going wrong. The issue is on my desktop monitor the photos look great. Overall vivid color, brightness, contrast etc. When I ...
3
votes
2answers
2k views

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 ...
3
votes
3answers
1k views

Why do I have to convert RAW files to JPEG to open them? [duplicate]

Possible Duplicate: How do I get started with RAW photography? I am a new to RAW shooting and recently bought a Nikon DSLR. I find that only the software which came with the camera can open ...
3
votes
2answers
119 views

How can I give an assitant rights to edit without having the possibility to download the image? [closed]

The situation is this one: we are a small photo company. We have a few people going out to shoot various assignments. When they return they hand me the memory cards and I download the images into the ...
3
votes
2answers
633 views

Which colour space should I apply Image sharpening filter?

I am trying to apply a Image sharpening 2D filter kernel(Laplacian) on a Image in my proprietary Image/Video processing pipeline(From Camera raw to final JPEG/MPEG). I plan to perform 2D convolution ...
3
votes
1answer
249 views

RGB colour correction of CCD camera images [closed]

I've developed an application which is able to communicate directly with a CCD camera (unbranded and obscure) and I'm able to capture and store the image from this camera. When the image is first ...
3
votes
3answers
5k views

Is there any good method to invert a negative image (duplicated with a digital camera) in Lightroom?

I made some duplicates picture (of negatives) with my digital camera using a bellows and a repro-dia. The image is obviously in a negative format but in RAW. Is the invertion function exists in ...
3
votes
5answers
10k views

How to get creamy skin tone in Lightroom

I googled some tutorials on "creamy lightroom", but most of what I found ended up turning my photos' skin tones too orange, too "vintage". I tried desaturating Orange to counter this, but the ...
3
votes
2answers
263 views

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 ...
3
votes
2answers
2k views

How to achieve misty look and vintage colors like Jaime Ibarra?

How are the color tones and the misty look achieved in the photo below? Does the technique/s have a name? (Note: link is NSFW.) Link to image - ...
3
votes
3answers
289 views

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 ...
3
votes
1answer
436 views

Which postcard mailing services are the best? [closed]

I have noticed several sites offering to let me upload a photo, some text and an address. They will then print a postcard with the image and my text and mail it for me. Some offer smartphone-apps and ...
3
votes
1answer
133 views

Can I extend dynamic range by underexposing and then downsampling (“binning”) my images?

In microscopy we often can sacrifice spatial resolution to collect more photons per pixel. Using sCMOS sensor and binning by factor of 2, we can get bump (up to 4x) in our signal-to-noise ratio (SNR). ...
3
votes
3answers
312 views

How to open a raw file in Camera Raw full size rather than cropped to in-camera aspect ratio?

On a recent photography holiday I took a number of photographs using the in camera option to change the image size to, for example, 16 x 9. The native image size of the camera is 4:3. I transferred ...
2
votes
3answers
133 views

What are similarities and differences between raw editing and film developing capabilities?

Raw images are supposed to be detailed output from the camera sensor(s), with more details that what can actually be printed or displayed on a screen. Effects like exposure compensation or white ...
2
votes
1answer
321 views

What are the anomalies in this picture of earth?

I was playing around with the New NASA pic of earth (posted July 20th 2015 on Nasa Goddard space flight center on Flickr). I've found this very odd structure on the bottom right corner that is pretty ...
2
votes
3answers
129 views

What education or certifications are needed to get work as an image processor or photo retoucher?

I am thinking about seeking employment in the area of photo retouching and image processing. What education or certifications would be good to help make this happen? And what online resources are ...
2
votes
1answer
198 views

What is the the product of two Fast Fourier Transfoms?

I am reading a book about image processing. I have found mention of a method for processing images. It is said that a special effect could be reached when we multiply two results of the Fast Fourier ...
2
votes
3answers
145 views

What are the exact pixel values (or ranges) for shadows/midtones/highlights in Lightroom?

In lightroom, different sliders impact different pixel intensities. I'm looking for the exact values (or approximate ranges) of the various levels: blacks: 0 - ? shadows: ? - ? midtones ? - ? ...
2
votes
2answers
251 views

What is subpixel sharpening?

What does sub pixel radius sharpening mean in this review of the Pentax K5IIs mean?How does it differ from regular sharpening? Now this is the same raw file, with a 301% .3 sub pixel radius ...
2
votes
2answers
153 views

How does a glare arise in images?

I know am sounding dumb but i have not been able to find a correct definition of glare What are the reasons it props up into images For example am taking a photograph of a fruit in diffuse light : ...
2
votes
1answer
279 views

Is there a technique for combining multiple images to create a sharper result?

I've been experimenting with photogrammetry for a while, and the main hurdle I keep tripping over is the clarity (lack thereof) of my images. Rather than spend a lot of money on a better camera, I'm ...
2
votes
3answers
706 views

What is Lightroom *really* doing when I change a Camera Calibration?

What does LR / ACR really do when a user changes the Camera Calibration setting? Here's Adobe's statement (for LR4, but I didn't find a newer one and there's no reason for this to change): Lightroom ...
2
votes
1answer
89 views

Are there any good “dispersion blur” image filters?

I would like to obtain an effect where pixels get spreaded locally. I tried to reproduce how such a filter would look, I hope you get the idea: before: after: Note: here I ran a blur, aded ...
2
votes
1answer
129 views

How to safely and efficiently remove frames of photo added by software?

How to safely and efficiently remove frames of photo added by software? I'm NOT talking about the physical frame, but the border/frame added by software such as PhotoShop. I'm particularly ...
2
votes
1answer
112 views

Is the 'mono' setting in smartphone cameras a form of grayscale?

In the description, my smartphone camera describes the 'mono' setting as being black and white, but it appears more to be grayscale - am I right in this assumption? Also, if it is grayscale, how is ...
2
votes
1answer
594 views

If I want soft focus, should I get the Canon 135mm soft focus lens or do it in Photoshop?

I always read that when possible it's best to "get things right in camera" which I always aim for - so following that line of thinking, would it be worthwhile to get the Canon 135mm f/2.8 soft focus ...
2
votes
1answer
358 views

How can I control exposure via a smartphone API when lighting changes? [closed]

I'm trying to create a smartphone application on iOS/Android that uses image processing. I'm experiencing the following problem: when I am recording and a new object (mostly white) enters the ...
2
votes
1answer
136 views

Recommended settings in Lightroom 5 when exporting to NIK / other plugs as TIFF?

When exporting to NIK or any other plug, Lightroom asks for some information. AFAIK, and the more I study the less I know, the exported file should be a TIFF (no good options there), ProPhoto RGB ...
2
votes
1answer
215 views

How can I export 16 bit tiffs with Mac OSX' imageing engine sips?

I'm playing around with Apple sips command. When I export a Canon raw file (CR2) to tiff via sips -s format tiff -out img.tiff img.cr2 the result is an 8-bit tiff, although the CR2 source is ...
2
votes
1answer
389 views

Gamma loaders on Windows 7/8: necessary or not?

I noticed that some monitor profiling software (like X-Rite i1 Display Pro, for one example) install their startup gamma loaders under Windows 7. Back in the XP days we used those utilities to load ...
2
votes
1answer
152 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 ...
2
votes
1answer
791 views

How exactly do RGB curves work and interact w/each other in Photoshop?

So I understand how a single curve works: If you create a curve such that R100 (in) becomes R50 (out), every pixel that has an R value of R100 becomes R50. Similar deal with the RGB curve: if you ...
1
vote
3answers
196 views

Can you take a picture of a faded docket and see the details again in computer?

Hi I have a very faded docket, where I can still read the details with bare eyes, but when I tried to photocopy and scan it, it just gave me a white docket. My last hope is using a camera. Please tell ...
1
vote
4answers
212 views

Seeking a way for “authoritiative”, proven method to prove that two photo images are “nearly identical”?

In usual discourse, when looking at an photographed image (A) - which is a JPG - and a slightly photoshopped version of it (A2), most people can intuitively compare the two and visually assess that ...
1
vote
2answers
279 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 ...
1
vote
2answers
73 views

Why does frame stacking alter colours?

I apologise in advance for the subject matter of my photos. I've not tidied the table for a few days. I needed indoor artificial lighting for the long duration of this experiment. Both images are ...
1
vote
3answers
99 views

Convolution algebra and capture, creative, and output sharpening

I'm making the reasonable assumption that software implements sharpening via convolutions. Convolutions are both commutative and associative. So... why do we talk about capture sharpening, local ...
1
vote
1answer
87 views

how can to convert single spherical distort image to rectangle image?

how can to convert single spherical distort image to rectangle image? I looked for more than a week I did not find the solution please help me.
1
vote
2answers
100 views

Flat fielding an image with two 1-D arrays

This is more of a math questions, but I thought I had a better chance of finding a camera enthusiast with a math background here. I've always flat fielded images using a two dimensional array with a ...
1
vote
3answers
644 views

How does the spectral sensitivity of different sensors affect the resulting photo?

I am learning about light and color formation but I don't understand how does the sensitivity affects an image. Take for instance the different sensitivities for two "cameras" for each RGB channel ...
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vote
1answer
127 views

Does shrinking the upscaled picture improve its quality (in terms of blur)?

Take a look at the following diagrams: The original picture: The upscaled (2x, bilinear) picture: In both cases the first item in the first row is the input image. There is its 2d fft next to ...
1
vote
1answer
339 views

How can I extract qualitative information from EXIF files?

I have bunch of EXIF files. I am looking for some heuristics to extract qualitative information such as if the picture is portrait or not, if the picture was taken in day or night, if the picture is ...
1
vote
2answers
62 views

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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vote
2answers
120 views

How can I convert a photo to a fixed palette with pre-defined weighted color proportions?

I am creating a physical mosaic from a photograph, where each mosaic tile will correspond to a pixel of the (scaled down) original picture. The problem is: my tile color selection is limited, with the ...
1
vote
1answer
107 views

2 Images, same object: tone difference and alignment [duplicate]

I would like to know a software which helps in post-production to calculate the general color/tone difference of 2 images. The images contain the same object, but arn't shot from the same position. ...
1
vote
1answer
122 views

Long Exposure Photo vs. Video [duplicate]

If I want to make some cool photos with long exposure times but not having a good camera that allows me to define the time, can I get the same result recording a video and make the superposition of ...
1
vote
1answer
210 views

How can I change the pixel data in a DNG while keeping all the metadata?

I am looking for some free tools that will let me easily process the pixel data in a RAW file (DNG or NEF) while keeping the metadata untouched. Are there any such tools? Use case: I am ...