What I mean by "true" resolution is the resolution at which the maximum available amount of real detail is present.  For an ideal picture this resolution is the same as the resolution encoded in the image file.  However, in other cases the actual true resolution may be less than the resolution of the image file:   If the image file was digitally scaled - for instance, if the camera has a "digital zoom" feature where it upsamples the individual pixels. If the image is not completely sharp and in focus.   In either of these cases, it is useful to me to have some mechanical method of identifying what the actual true resolution of the image is independent of what the image file says.  How can I do this?  Is there some software or algorithm which can take an image and analyze it and tell me the highest resolution it can be displayed at while showing detail at the resolution?  My initial naive expectation that it should be "obvious" and easy to determine by some simple mechanism such as compressed sizes is thwarted in cases where the upscaled image has noticable artifacting or noise not present in the original.
120808
Let's take image A: 2560*1920 pixel image in perfect focus. Sharp as a razor. That's 5 Mpix.  Let's take image B: image A resized to 5120*3840. It's now a 20 Mpix file, but there's no new data in the image, so - using common sense - it's still just a 5 Mpix file, just "bloated".  Theoretically, one should be able gradually to reduce image B's dimensions until reasonable sharpness is detected (bringing it as close to image A as possible, although without actually comparing them at this point), and thus derive the image's "true" megapixel count: the size below which imagery is starting to lose its details.  This value could easily be used to determine the usefulness of a photo - if I shoot it slightly out of focus, I can still print it in a smaller size, and no-one will notice. Or, it could help with assessing lens or sensor quality - if a 24 Mpix camera is unable to capture an image with more than "true" 8 Mpix, then something isn't right.  So, cutting to the chase: is there a software program that does just that? Or am I doomed to writing my own?    From a comment by the OP to one of the answers:     I need to measure how much detail is my positive transparency scanner really getting, before I scan a collection of about 2000 old slides and consider it digitized. If I set it to optical 19200 dpi or something, and it keeps producing images with detail lost, equal to, say, a 5 Mpix camera, then I'll know it's bad.   This is the actual problem the question wants to solve. Everything above is about one perceived solution to that root problem.
7093
How to resize an image or selection without resampling the pixels? I have some pixel art that I want to enlarge without losing the hard, non-anti-aliased, pixel edges. In other words, 1px should become 4px of the same color— fake big pixels. Is there any way to achieve this procedurally?  Example (of what I don't want):  before resize:    after resize:    Open to other tools/methods beyond photoshop, thanks in advance.
52649
JPG files use  (I've never heard of any camera that uses the alleged 12-bit-per-color-per-pixel extension) and is a compact way of storing images.  RAW files are huge but have the full image data from the image sensor which is likely to be more than 8 bits. (judging from recent DSP specs I would assume 12 bit ADCs are the norm... but how would you actually find out how many bits a particular camera provides?)  Is there anything similar to JPG which stores the file in a form that allows lossy compression for high spatial frequencies, but has more dynamic range than 8 bits?
58216
I just made a video in mov-formate containing 300pngs in 4k. Every single png ist roughly 6MB in filesize. The mov-file is just 8MB. Seems weird to me. Is there maybe a quality loss in the video? The video looks fine but the size just seems so small.
102566
When I upload this 110x110px image with 100px resolution it seams blurry.    Have any idea what's happening? Do you think it's the color?
61605
Why do high resolution cameras shoot stills at high resolutions, but only typically shoot video at 1080p which is about 2 megapixels?  For example I have a Sony-NEX 6 which can shoot stills at 16 megapixels but only 1080p by 1920p video.  Also how do digital cameras separate the frames in video if the lens shutter never closes?  And if you can shoot video at 30 fps or 60 fps then why can't cameras have a continuous drives at 30 to 60 fps?
57527
Background  A large number of screen captures have been scaled 300% at 288dpi. They appear correctly when embedded in OpenOffice, but not LyX.  Problem  Images that do not extend beyond the margins (small images) appear perfectly. Images that are too big extend beyond the margins.  Attempt #1  \setkeys{Gin}{width=1.0\textwidth}    However, that code scales the smaller images to also fit the width, which is undesirable. (The smaller images become distorted.)  Attempt #2  Didn't attempt this, but it looks useful.  % Redefine includgraphics for avoiding images larger than the screen size % If the size is not specified. \let\py@Oldincludegraphics\includegraphics  \newbox\image@box% \newdimen\image@width% \renewcommand\includegraphics[2][\@empty]{%   \ifx#1\@empty%     \setbox\image@box=\hbox{\py@Oldincludegraphics{#2}}%     \image@width\wd\image@box%     \ifdim \image@width&gt;\linewidth%       \setbox\image@box=\hbox{\py@Oldincludegraphics[width=\linewidth]{#2}}%       \box\image@box%     \else%       \py@Oldincludegraphics{#2}%     \fi%   \else%     \py@Oldincludegraphics[#1]{#2}%   \fi% }   Source:   Attempt #3  % Resize figures that are too wide for the page \let\oldincludegraphics\includegraphics \renewcommand\includegraphics[2][]{%   \makeatletter%   \def\maxwidth{\ifdim\Ginnatwidth&gt;\linewidth\linewidth%   \else\Ginnatwidth\fi}%   \makeatother%   \oldincludegraphics[width=\maxwidth]{#2}%   Packages  Using graphicx.  Other package suggestions are welcome.  Question  Without adding LaTeX code to every image that exceeds the margins, what can be done to resize just those images that are too big?  Example  The following image is an example of many, many images that must be scaled back to fit the page width:    Related
108222
Some of the newer tablets and also Notebooks (notably the iPad, Macbook Pro and the Nexus 10 tablet) use displays with ultra-high resolutions at around 300 dpi. This makes text look very, very good, but it also means that images that are not adapted to that resolution can look rather bad in comparison.  Here are some crops from a screenshot from my Nexus 10:    and    These show that the StackExchange button and the logo, which contain text and hard edges, looks noticeably softer on a high-resolution display. This is of course no big deal, but it is very noticeable.  It would be nice if at some point some of the common images on SE sites that contain text or other hard edges would be served as high-resolution versions to devices with such high-resolution displays. This is obviously not a critical issue, but it would be nice if it could be tackled at some point.
40206
I'm doing magnification and lens in class currently, and I really don't get why virtual and real images are called what they are.  A virtual image occurs the object is less than the focal length of the lens from the lens, and a real image occurs when an object is further than focal length.  By why virtual and real? What's the difference? You can't touch an image no matter what it's called, because it's just light.
105608
I have been using blender for about a year now and have only just started to notice that all my pictures are actually not that HD. If you zoom in on a render just once, you can see each individual pixel colour. I don't know if this this is a big or if it is something I can do or even if this happens to everyone. Please help as its really bugging me now.  Here is an example of a render that is a bit pixelated:  Save the picture and open it in fullscreen and zoom in just a bit.
75620
From a technical perspective, what exactly is RAW and how does it differ from JPG or bitmap images? I'm not asking about the pros/cons versus another format, but rather what constitutes RAW format, how is the data stored, how does it differ from JPG (other than lack of compression), and how is it different than bitmap?
116012
I want to display an image at 'true size' in my application.  For that I need to know the pixel size of the display.  I know windows display resolution is nominally 96dpi, but for my purposes I want a better guess.  I understand this information may not always be available or accurate (e.g. older CRT displays), but I imagine with the prevelance of LCD displays that this should be possible!  Is there a way to get the pixel size of my display?  Is there a way to determine if the pixel size is accurate?  .NET API's preferred (I couldn't find them), but Win32 is OK too, I'm happy to P/Invoke.
5140
I have a Casio EX-S12. It has a setting for image size, but also a separate setting for what it calls "image quality". There are three image quality values: "Fine", "Normal", and "Economy".  The Casio manual is not clear on what image "quality" actually means -- specifically how it's different from image size. All they say is that the "Fine" setting "helps to bring out details when shooting a finely detailed image of nature that includes dense tree branches or leaves, or an image of a complex pattern." I'm confused because isn't this what image size is all about (more pixels = more detail)?  In terms of memory usage, the manual also says that for a 5 megapixel picture, a "Fine" image takes up 2.99 MB, a "Normal" image takes up 1.62 MB, and an "Economy" image takes up 1.12 MB, so this "image quality" setting of theirs is certainly having a significant impact on memory usage.  My question is, what exactly is "image quality", if it's not image size? What is the "thing" that is taking up additional memory?  Thank you.
64846
Changing quality of the JPEG when saving an image, changes the file size. For eg. I have the following image. Dimension: 243px x 53 px Quality:100% File Size:9.7kb Background:      If I edit the image, keeping the dimensions and Quality same, the file size still falls to 6.1kb.      Problem: I am using Fotoresizer, which has a batch Quality change option, but due to the above problem, you cannot predict file size from quality alone. So when I batch change quality of a set of 200px x 300px images set at 20% quality, some files will turn out at 6kb, whereas others will turn out at 15kb, when the file size I want is 10kb.  Is there any program or programmable solution, which lets me save all files in a range of 10-11kb, without me manually changing the quality slider to change file size each time.
21364
Through my NAS at home I store and backup all my photos on Google Drive. These photos also show up on Google Photos. I use Lightroom and convert all photos to DNG when copying to my NAS.  When I look at the photos in Google Photos the image is rather small. Clicking the (i) info button tells me the image has a resolution of 1024x680, file size 9.8 MB and a MP of 0.7. This is probably just a preview or thumbnail of some sort, but how do I view the image in larger resolutions in Google Photos?
117201
I'd like to start making prints, but all of my work is set at a resolution of 72. Are there any negative effects to increasing the resolution to 300? I'm very new to this, but from what I've read so far: higher res = nicer looking prints.  I apologize if a similar topic has been posted before, I just wanted to know if there was any pressing reason why I should not be doing this.
22748
All of my pictures come out super blurry if they are anything bigger that 5x7 and I want to fix it. So how do I change the resolution? Is it something I have to do BEFORE I take the pictures or am I able to do it after? I need help! Thank you!