Screen Capture File Size Discrepancy

Can someone please explain to me why the screen capture (cmd-shift-4) generates such huge files?
I made a screen capture which was saved to my desktop as picture-1.png. Examining the file's properties showed that the file size was 1.03MB.
Next I opened the file in Photoshop, used Save For Web, and set the file type to PNG-24. This file, which in every way is identical to the original except for file size is only 11kb.
Why is the OSX screen capture larger by a factor of nearly 100?

Just by way of illustration, when I take a PNG screenshot of my 23 inch LCD I get a 4.4 MB file. But only if the desktop picture is all that is showing.
By contrast, a PNG screenshot of the same screen with OSX windows covering the desktop is only 360KB. Why the discrepancy?
PNG compresses using a raster notation that works at its best when continuous identical pixels cover some horizontal stretch. Just like Mac OSX windows. Noncontinuous colored pixels are very hard for PNG to compress, since there are very few identical colors. This is why photographs should be compressed with JPG (which uses a color averaging scheme) and web animations with PNG.
The OSX screenshot format uses 32 bit PNG, which is 16.7 million colors. So if you are reducing the bit depth to 24 bits, that is a huge reduction in filesize. Especially if the 24 bit format converts colors to identical runs, which compress better in PNG. I am talking about color variation you can't even see. That would explain the "factor of nearly 100" you noticed.

Similar Messages

How do I add time/date stamp to my screen capture file names?

I'm on mac osx.
I'm trying to add time/date stamp to my screen capture file names. (at the moment it's just 'Picture 1' etc..)
I've tried the following command in terminal but have not had success. please help!!
defaults write com.apple.screencapture name "datestamp" at "timestamp"
killall SystemUIServer

Surely someone else will provide a better solution. Meanwhile, however, you might want to try the following script. Copy and paste the script into the AppleScript Editor's window and save it as an application. Then drop your screen capture files on the droplet's Finder icon.
on open theDroppedFiles
    tell application "Finder"
        repeat with thisFile in theDroppedFiles
            set theFileName to name of thisFile
            if (word 1 of theFileName is "Picture") and ¬
                (word 2 of theFileName = word -2 of theFileName) then
                set theExtension to name extension of thisFile
                set P to offset of theExtension in theFileName
                set theCreationDate to creation date of thisFile
                set dateStamp to short date string of theCreationDate
                set timeStamp to time string of theCreationDate
                set name of thisFile to "Screen Shot " & dateStamp ¬
                    & " at " & timeStamp & "." & theExtension
            end if
        end repeat
    end tell
end open
Message was edited by: Pierre L.

Screen Capture file location?

Suddenly my screen captures are sent only to the clipboard instead of the desktop as they used to. How can I change that back? I'm using ShiftCtrl+Cmd4 or ShiftCtrl+Cmd3.
Also, where would you change where the screen capture files ends up?

You're pushing too many buttons. The additional ctrl button copies to the clipboard.
See the Preference panels>Keyboard>keyboard Shortcuts for the list of buttons.

Any way to limit DV captured file size?

Hello all -
When capturing from a DV camcorder when the source is not timecoded, is there a way to cap the max file size? Ideally I'd like to set a size limit, eg. 650mb and then have the files split into project 01.avi, project 02.avi, etc.
Thanks,
Steve

So I gather the answer is No, Premiere Elements cannot split AVI files when capturing from DV camcorders, except by timecode?
I realize there are other packages I can pay for that support the feature but I expect Premiere Elements (at least by v8) to have that capability.
In any event, Easy Video Splitter (doeasier.org) is now free and does the job well.

Incredibly strange file size discrepancy only appears in image files (jpg, gif, png)!

I'm creating a bunch of banners for google ads, yahoo ads, ...etc in Photoshop on my Mac OS!
The .gif files of these banners appear to TRIPLE in size when on the MAC (>150KB), but when transferred to windows; the real file size shows correctly! (<50KB)
It is not a result of the base2 vs base10 discrepancy since the difference in size is simply too big, and it only happens with files created on Photoshop on my Mac.
The reason I know that windows is showing the correct size while my Mac OS is displaying the wrong size, is that the file gets approved by google and yahoo ads, even though Mac OS shows that it surpasses the size limit (50KB) three times over!
This isn't an isolated incident either, all image files created in Photoshop on the MAC continue this weird behaviour! However, files downloaded from the net appear to be consistent on both operating systems!
One example is the attached screenshot:
Explanation, please??

Geez, sorry I offended you Mr. Jobs (incarnate)!
You came in here with a three ton chip on your shoulders. Did you really expect sunshine and puppies in return?
No, I expected useful help, and I got it from Jeffrey Jones. Thanks again Jeffrey!
I mean, when you move or upload it, it loses this data association anyways!
To a drive which doesn't support Apple's AB tree structure (NTFS, FAT, FAT32, exFAT), yes. To another HFS+ drive, no.
What about uploading the file to the cloud?? Does it lose this association or not?? And does anyone really care about the data in the Resource fork?
This "Resource Fork" means nothing to the file owner, only to the OS and the Drive. Therefore, it shouldn't be added to the total. Period. Because its not part of the file, its part of Apple's tree structure! This is really a simple concept, not sure why you are bending over backwords to defend a clearly stupid oversight from apple!
There's no reason to force me to use the command line to get the real file size of a GIF! There's just no excuse for that!
If an OS is saying it is fetching file size information for a single file, it should do exactly that! Not add hidden Resource Forks that are part of the OS's internal workings
OS X is fetching the file size. It's file size, not the way a different OS would report it.
There is no such thing as it's file size. A file size is a file size, accross all platforms, on the cloud, wherever!
A GIF file should have the same file size whether its on windows, linux, unix, darwin, freeBSD, or anything else. The only time its weight should vary is in outer space!
That is why I'm surprised that they are breaking simple UI Design rules.
The User Interface has nothing to do with the file structure of a drive.
I don't care about the structure of the drive!! Neither should you, neither should the average user!
A good UI should NOT concern the user with this! The average user doesn't care about these Resource Forks, and will never try to view them, therefore, there is no logical reason to add up their file sizes to the total size of each file, and then to make things worse, hide that fact! That only creates confusion, and it makes it so much harder for a designer like myself to view the REAL file sizes of my image files! Now, whenever I'm on my MAC, I will have to run command line scripts to be able to see if my GIF files (that I work on EVERYDAY) meet the file size quota, because Mac OS adds up hidden files that I have no use for and gives me the WRONG file size!
Let's say this again: when you select a file and click get info, you should get the info for the file you selcted. Nothing more, nothing less! I don't care if the file structure creates an entire colony of hidden files, they should be completely hidden to me, and if not, the Get Info dialog box should at least give me two sizes, one is the REAL file size, and the other is the added up file size for the Resource Fork as well (although I can't think of any good reason why it should add up the Resource Fork size anyways)!
do you think it is at all logical, that when you select 300 or so files, and click Get Info, that it open 300 windows at once each showing separate information for each file? Or does it make a lot more sense, intuitively, to get the total tally of all the files selected added up, without having to hold down shortcut keys when clicking them to do so?
Yes, it is logical because that's what you, the user, told the OS to do. You wanted the Get Info data on 300 individual items. I don't know about you, but I avoid the menu bar as much as possible (your reference to avoiding shortcut keys). Command+I will always give you singular Get Info dialogue boxes.
No, that's not what I told the OS to do. I selected 300 files cumulatively, therefore, I should get the cumulative info for all the selected files. That's just common sense. Every other OS seems to get this!
And I'm hard pressed to find anyone who has found a use for having 300 get info boxes open at the same time. Therefore, that shouldn't be the default.
Will you start defending apple's decision to stick with the one button mouse for all these years depriving us from the all important context menu as well?? There was absolutely no good reason to do that, just as there is absolutely no good reason to do this!

File Size Discrepancy Between Photoshop & the Finder

I'm trying to be as brief as I can, so here goes. The specific application (PS) is irrelevant, I think. This is about why an app shows one file size & the Finder shows a different file size. In this case, it's a huge difference, due to the file being an image.
I imported into PS CS, from a CD, an original image, which the Finder shows as 269.4 MB. The file format is TIFF, and the bit-depth is 16, not 8. The Finder shows it as a "TIFF Document." Now. I did a Save As and edited that as a master image file. So, I have two files: the original and the master.
I substantially cropped (deleted) pixels in the master file. So, at the same 16-bit depth, the master file should be smaller in size than the original. Right? However, the Finder shows the file to be 433.6 MB in size! Photoshop shows the file to be a more realistic 185.8 MB in size. Why is the Finder showing such a huge file size? Why is the Finder storing 247.8 MB more than I need? The Finder shows this file as an "Adobe Photoshop TIFF file," so there has been a change in format. The file is flattened; no layers, etc., are involved.
One clue could be that the Finder is storing the larger file size to accommodate Photoshop. If one multiplies 185.8 MB by 3, the result is close to the 433.6 MB figure. The 3 stands for the three color channels (red, green, blue) of each pixel (data element) in the image.
The original image, however, is stored correctly by the Finder. Photoshop and the Finder agree on the 269.4 MB file size. If the above scenario were true, the Finder would be storing the original file at three times the size as shown in Photoshop. In other words, there would be consistency in what the Finder is doing.
I suppose I could just ignore the discrepancy, but I have hundreds of images to process, and I don't want to have to go into PS every time to get a true reading of file sizes. The Finder should be accurate in doing that.
I may be in the wrong forum re: Photoshop, but here I think I can find some expertise re: the Finder, since the Finder's storing procedures are in question, to my mind. It's definitely an app/OS interface problem, as I see it. Simply, I edit a file downward in data, save it, yet the Finder saves it at a larger size.

...do you think a lot of cloning & healing brush might have added to the file size, even though I cropped the image?
Yes, depending on your History settings. The more you work on an image, the more history it accumulates. The more different states and sanpshots you save in the History palette, the bigger the file gets as you work on it, because you're storing (within the file) complete information about the file's state before and after every individual change you make to it. What I don't recall is whether that all gets saved to the file in a Save As, or whether the history is flushed each time the file is Saved.
I should warn you that I am by NO stretch of the imagination a PS expert. I was still using PS 5.0.2 until last February, when I upgraded to CS2 (knowing it will be years before I have enough hardware horsepower to run CS3). I'm a rank beginner with CS2, and if someone else wants to jump in here and point out that I'm all wrong, it will be no surprise to me. And because I never used CS, I don't know whether what I'm describing in CS2 is even relevant here.

File Size Discrepancy

I hope somebody can help me! I have a Quicktime self-contained movie which in the "Get Info" option says that it's 2.26 GB, but in the Quicktime "Show Movie Info" option it says it's data size is 55MB. Why the discrepancy?
Power Mac G5 Dual 2.3 GHz Mac OS X (10.4.7)

I don't understand. Do you mean the higher figure is it's actual file size?
If I assume both of the above readings were in fact taken using the same file as the source (i.e., you did not use the original source file for the first measurement and a final converted file for the second), then yes, that is exactly what I mean. I don't know how you measure the size of a file, but I take it to be the amount of space required to store the file on a hard drive. Now it is possible that a file can be corrupted and contain many "empty" or "unused" data blocks. So I cannot rule out this possibility here. If you have reason to doubt the "file size," simply try copying it from one hard drive to another and see if both copies require the same amount of space for storage.

Screen Capture files are corrupted

I use the built-in Screen Capture all the time....Command-Shift-3 and Command-Shift-4.
As recently as two days ago, it worked beautifully.
Today, it's not working correctly. The files get saved to the desktop, but they are corrupted. I can make out the image that I captured, but it looks like the horizontal setting on old cathode ray TVs is waaay out of sync.
I've tried a different user on the machine. I've tried changing the format from png to jpeg to pdf and back to png. Same result.
This is weird.
Any ideas?

OK, weird. The problem has 'gone away' without doing anything specific. I didn't even realize it - I just did a screen shot because I needed it and then sent it to the person who needed it. Only later, did I realize that I had had problems just yesterday.
I didn't even get a chance to try the suggestions listed above.
By the way, all three versions of the file were corrupted: the desktop icon, the Quick Look version and the actual file as seen in Preview.
If it happens again, I'll be back.
Thanks for the help people. I hope to return the favor.
Message was edited by: Zonker in Russia

Screen Capture File Type (PNG)

I would like to change the file type, currently PNG, of OS X's screen capture. Is there a preference I can change to choose different file types? I would like it to be JPEG.
Thanks for your help
John

Found answer by using terminal.
Alright, start up Launchpad. Go into your Utilities folder and start up Terminal. Just type in what I show you & I'll also included it in the text below so you can simply copy paste it into your Terminal.
defaults write com.apple.screencapture type jpg
Now, the last part jpg is obviously saying that we want the default to be a JPEG. You can actually change this to any image format you want. You can change it to a BMP, TIF, PDF, whatever. Once you have that hit enter and type:
killall SystemUIServer
Make sure to capitalize it just as I have here. Once you have that hit enter. Ok Lets take another screencpature and see how the info has changed. Command+Shift+3 .. Right click .. get info ..
https://www.youtube.com/watch?v=6SD7rAfBJPk

Vault (external) file size Versus Aperture Library (internal) file size discrepancy?

Using Aperture 3.3.1 (all my images are Referenced). I created my first vault on an external hard drive. The Vault.apvault file size is 32.8 GB. My Aperture Library.aplibrary file size on my iMac hard drive is 81.6 GB. So I am wondering if I have a full back-up in Vault or not. Seems like a large discrepency in file size. Any thoughts or help would be appreciated.

Do any Images that you don't expect show up when you filter "Photos" using the Rule "File Status" with the argument "Managed"?
If not, then close Aperture and repair your database. Instructions are on the Apple Aperture trouble-shooting page.
Does that make any difference?

Photoshop file size Discrepancy

Hey Guys.
I have a photoshop file which while editing states what I believe is the flat/layered file sizes down the bottom left of the screen of 116.7M/255.4M.
But when I save the file Finder shows the file size as being 1.53GB.
Is this normal? What am I missing? See below screen grab

The size in Photoshop is pretty accurate.
But it has nothing to do with file size.
Please read the documentation again.
Files are compressed, and different file formats will compress differently, and the amount of compression is very much related to the image content.
That's why Photoshop never displays file sizes except for estimates in the JPEG and the Save For Web dialogs.
The sizes displayed in Photoshop's status bar and info palette are the size of the document in memory, or the flattened size of the image (uncompressed).

Screen Capture File Format

Does anyone know a way to change the default file format in the Mac OS screen capture utility to a different format other than PNG? Thanks.

cbenham wrote:
Does anyone know a way to change the default file format in the Mac OS screen capture utility to a different format other than PNG? Thanks.
There are two default screen capture mechanisms in Leopard:
The direct ⌘ shortcut, and the application, grab.
I presume you are referring to the ⌘ shortcuts since the default for grab is tiff
⌘-Shift-3 = Screen
⌘-Shift-4 = Selection
⌘-Shift-4 + Spacebar = Window
To change the format, in a terminal enter
defaults write com.apple.screencapture type image_format
where "image_format" can be
tiff
jpg
pdf
and possibly others.
When using the terminal, you are on your own and if you are unfamiliar with it, be very careful.
Message was edited by: nerowolfe

Screen Capture (file format) used to be pdf

Is there a way to change the default file format for a screen capture. The file format in OS 10.3 used to capture as a PDF. Now the format is PNG. I know you can open the file in preview and resave it.
I just want to see if there is someway to change preferences or something so it will default as a pdf file.
thanks

Hi, amantia and costicladop —
amantia, welcome to Apple Discussions!
There are various options to accomplish your objective.
OnyX 1.6.5 (a free utility) and Cocktail 3.6.5 ($14.95 shareware utility) offer the option to change graphic file format with a "single click" — in OnyX »» Appearance »» Screen Capture and Cocktail »» Interface »» Misc. »» Screenshot file format, respectively.
They're both just implementing Terminal commands — which provide another option.
bmp, gif, jpg, jpg-2000, pdf, photoshop, pict, png, sgi, tga, and tiff options are available in both utilities.
Hope this helps . . .
Regards,
Dean
p.s. costicladop — following your link engages an automatic download. (Duh.) Wanting to read something first, I went to http://www.arenasoftware.com/ — which forwards to http://www.digitalarena.co.nz/. The software page on that site only mentions three software products, none of which is shotChoice. Could you provide a descriptive link? Thanks!

Screen capture file storage

It looks like Jabber stores screen captures forever under My Documents/MyJabberFiles. Does Jabber jimit the growth of these? Is there a way to change this to use the temporary files directory so that they can be easily purged?
The endless growth of screen captures and chat history isn't a good behaviour.
Thanks,
Eric

I just came across this "problem" today as well. File transfers are stored in this location as well. My concern is not only from an excessive file growth problem, but also a litigation discovery problem. We don't like to have any data on our desktops that is discoverable. I would like to be able to change this default location for screen captures and file transfers to a network location. Or even better, an option to change the location to a network location and purge after x number of days.
We do not keep chat history for the same reason, to avoid having to retrieve files from desktops if a discovery request comes in.

Capture file size

I just captured approx 15 minutes of DV video from an old sony Hi8 camera and the file is over 3 gigs! 15 minutes of high quality DVD video would only be around 500 megs. What would be the best way to get the file size down to the 500 meg range without sacrificing much or any quality? Would PP be the best tool for this or should I go with something like Nero Recode?

A quick, step-by-step Tutorial for Encore (Not Dynamic Link) http://www.pacifier.com/~jtsmith/Encore.txt
The individual CS5 pages also have links to the CS4 user guide pages
CS5 User Guides - online and PDF (right click PDF link to save PDF to your hard drive)
http://blogs.adobe.com/premiereprotraining/2010/08/help-documents-for-creative-suite-5-pdf -and-html.html

Screen Capture File Size Discrepancy

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