223
votes
Accepted
What does an unprocessed RAW file look like?
There is a tool called dcraw which reads various RAW file types and extracts pixel data from them — it's actually the original code at the very bottom of a lot of open source and even commercial RAW ...
- 144k
74
votes
Aren't all digital images ultimately just pixel values between 0 - 255?
Sorry, but your basic premise is wrong: an image can be encoded as an array of RBG pixels with 8 bits per value, but there are a lot of other ways:
one channel with one bit/channel (pure black and ...
- 3,181
51
votes
Aren't all digital images ultimately just pixel values between 0 - 255?
If at the core, photos are just 3 channels of pixel values [0, 255] X RBG,
But photos are not "just 3 channels of pixel values" even "at the core." Computer screens are typically made up of an array ...
- 31.7k
35
votes
Accepted
Changing JPEG to RAW to use on Lightroom?
In my opinion, none of the other answers addresses the obvious misconception in the question:
There is no use in converting a JPG (comparatively low quality) to a RAW file (high quality), because you ...
- 446
33
votes
Can you "open" RAW camera files?
It's linguistics.
Of course you can open a raw file, as the term "to open a file" has a very broad spectrum of different, but related meanings.
On a low level, "to open" just ...
- 1,359
28
votes
How do I make my image comply with the requirements of this photography competition?
"we may require the originals of the awarded photographs to be submitted by the relevant participants, with a short side of minimum 2200 pixels and bit depth of 300 dpi."
and
" ...
- 176k
20
votes
Is a JPG guaranteed to produce the same pixels?
Short Answer
No, decoding is not guaranteed to always be the same. However, the differences are guaranteed to be very, very small.
ISO Specifications
The International Organization for ...
- 301
19
votes
Aren't all digital images ultimately just pixel values between 0 - 255?
In addition to @remco's fantastic answer, I want to add why there are different codecs for (roughly) the same purpose.
Codecs are designed to:
Be lossless vs. lossy
Encode fast vs. reduce filesize
...
- 6,478
19
votes
Changing JPEG to RAW to use on Lightroom?
In the absence of real raw files, the JPG is your "raw". Most image editors, including Lightroom, can open or import JPGs. You may choose to save in another format while editing, but do not lose or ...
- 27.1k
18
votes
Accepted
Does converting image file formats affect quality?
Going from JPG (which is a lossy format) to any lossless one (like PNG) does not.
Going from any format to a lossy one, yes, including JPG to JPG. It could be too little to notice, and using the same ...
- 25.4k
15
votes
What makes RAW files difficult for manipulation?
Nothing makes raw files difficult to manipulate for someone with the right expertise and tools. It's just that there aren't many folks around who have those tools and expertise.
The tools needed to ...
- 176k
15
votes
Can you "open" RAW camera files?
It is all already said, I just want to make a meme and a philosophical exercise.
Here is a JPG file opened... on a program that does not make a "preview" of the file.
I prefer one that ...
- 25.4k
13
votes
Aren't all digital images ultimately just pixel values between 0 - 255?
There are several reasons why this assumption is incorrect, and they all come down to one thing:
What scale are you actually using?
And that can be broken down a little further:
What is 255?
"...
- 144k
13
votes
What does an unprocessed RAW file look like?
It's a really really big grid of numbers. Everything else is processing.
- 271
12
votes
Accepted
Can RAW image files deteriorate over time?
RAW files no more deteriorate over time than a DOC file would. As long as you store them correctly (with backups of course) the file will be fine.
It's true that the software that you use to process ...
- 511
11
votes
How are 360° photos stored and processed?
How are 360° photos stored? Do they have a special file format or are they projected onto a regular png/jpeg?
360x180 panos are stored a number of different ways, but most commonly as a single image ...
- 53k
11
votes
Accepted
Is SSD a safe replacement for HDD image storage?
The answer is always the same: you should never rely on having just one copy of anything important. Any difference in reliability between magnetic drives and SSDs is essentially irrelevant - they are ...
- 22.2k
10
votes
What makes RAW files difficult for manipulation?
A RAW file is little more than a container for the output of a camera sensor. It has to be processed into an image which gives it full color information at each pixel. As such there are no programs ...
- 103k
10
votes
Accepted
Which file format is recommended for black and white photographs?
Shoot in RAW, and export on whatever format you like. JPEG for example.
For print it can be on TIFF. And you could export at grayscale at 16 bits. But that is only for specialized usage. For most ...
- 25.4k
10
votes
Accepted
How are 360° photos stored and processed?
There are no finer details.
Let us start from the beginning.
A file
You have a camera with a lens and the file stores what was projected on the sensor.
You can change the lens, for example to a wide ...
- 25.4k
10
votes
Aren't all digital images ultimately just pixel values between 0 - 255?
If at the core, photos are just 3 channels of pixel values [0, 255] X RBG
That is a seriously broken assumption and the rest of your question is simply not answerable without breaking away from it.
...
- 823
10
votes
Can you "open" RAW camera files?
You can open a RAW file the same way you can open a JPEG file. Both need to be interpreted by software to show useful data. You might say that the RAW file has many different interpretations, but the ...
- 7,209
10
votes
Can you "open" RAW camera files?
I told him, since the invention of “raw editors” like Lightroom and camera raw in photoshop, you can certainly open raw files, the software simply shows a visual representation of the raw data and ...
- 176k
9
votes
Is a JPG guaranteed to produce the same pixels?
No, you can't depend on decoded JPEG images being bit-for-bit identical.
As an example, I tried viewing the image at the top of this page in two different browsers: Chrome 53.0.2785.143 and Internet ...
- 1,495
9
votes
Is it not ideal to save image as PNG for printing?
Yes, PNG is theoretically better than JPEG in preserving the ultimate image quality, but in practice this is the kind of exactness we don't really see, especially in print, where the physical ...
- 5,069
9
votes
What does an unprocessed RAW file look like?
I know it's already been answered quite well by mattdm, but I just thought you might find this article interesting.
In case the link goes down, here is a summary:
The human eye is most sensitive to ...
- 99
8
votes
Aren't all digital images ultimately just pixel values between 0 - 255?
No, an image is not just RGB values in the range 0-255. Even if you ignore storage formats, there are many ways to describe color. Here are some examples:
Red, green and blue components (RGB)
Cyan, ...
- 211
7
votes
Accepted
Should I resize photos before or after image optimization?
The "ImageOptim" tool pulls together a bunch of other things, and in the case of JPEG files, the relevant thing is the MozJPEG optimizing encoder. If you use this encoder and then resize and save with ...
- 144k
7
votes
Accepted
Is the Preview file always the photo taken by the camera?
When you take a photo with a digital camera, The camera collects the raw data from the image sensor, processes it, and creates a JPEG preview image. This preview image is attached to the main image ...
- 176k
7
votes
Fast, lossy compressed, 10 bit image format (Or 12 bit or 16 bit)
No single file format currently fits your requirements. Your current solution is the most practical for now. JPG for viewing and export. TIF/PNG/RAW for preservation and editing.
Most image ...
- 27.1k
Only top scored, non community-wiki answers of a minimum length are eligible