Format Question

[rodrigue]

Re: Format Question

...
Choices usually are JPEG, JPEG-2000, OpenEXR (have no idea what this is), PDF, PNG & TIFF...

FYI:

This is what Wikipedia says:

OpenEXR is a high dynamic range imaging image file format, released as an open standard along with a set of software tools created by Industrial Light and Magic (ILM), released under a free software license similar to the BSD license.

See also: http://www.openexr.com/

[Frank Zwolinski]

Re: Format Question

Did you check out the Library of Congress site that I mentioned on Jun 26th? If so, were the suggestions helpful? I'm thinking I'll go through the info and pull out the lists & info that would apply more to us.

Kaye,
I did look at it briefly but I need a bit more time to check it all out. Excellent source, Thank you.
Frank

[Frank Zwolinski]

Re: Format Question

At the bottom of the Finder screen, there is a drop-menu where you can change the format. Choices usually are JPEG, JPEG-2000, OpenEXR (have no idea what this is), PDF, PNG & TIFF. Some of the choices allow you to determine the quality (kb & MB) & other determinations using a slide or another drop-menu.

I believe you can do this with anything that will open in Preview, including the above formats.

Hope this is helpful.

Kaye, Yes, quite helpful! I had not checked out the quality changing.

Frank

[kmgenealogy]

Re: Format Question

FYI:

This is what Wikipedia says:

OpenEXR is a high dynamic range imaging image file format, released as an open standard along with a set of software tools created by Industrial Light and Magic (ILM), released under a free software license similar to the BSD license.

See also: http://www.openexr.com/

Thanks, Rodrique. Looks like it's a format for very high-end users.

[Kate McCain]

Re: Format Question

It's Command-shift-4 then drag through what you want to capture. It makes a camera shutter click and puts the file on your desktop.

This article tells how to change from PNG to JPG (although you have to issue a terminal command and "kill" a process. Not for the squeamish! But you only have to do it once.)

http://theturninggate.net/2012/08/change-screen-capture-file-format-on-mac-os-x/

A lot of people swear by Snag-It and other screen capture programs. I already have an image editor (PhotoShop) and can use the built-in screen capture described above and they work fine for my purposes.

For what it's worth, I really love GraphicConverter. It's a shareware program that will change any image format into any other image format. You can also edit and tweak the images a bit (which has helped when my digital images taken indoors were a weird color.

[Tom Robinson]

Re: Format Question

It's Command-shift-4 then drag through what you want to capture. It makes a camera shutter click and puts the file on your desktop.

This article tells how to change from PNG to JPG (although you have to issue a terminal command and "kill" a process. Not for the squeamish! But you only have to do it once.)

http://theturninggate.net/2012/08/change-screen-capture-file-format-on-mac-os-x/

Not sure why you'd want to do this?

The default PNG format is 'lossless', meaning it's an exact representation of the screen.

JPEG is a 'lossy' format, which means some information (quality) has been lost (and will be every time you edit the file).

[donworth]

Re: Format Question

Not sure why you'd want to do this?

Tom,

It has been my experience that JPG on medium compression at 600dpi produces a much smaller file and a better image than PNG at 300 dpi, even when PNG is compressed. For example, I just saved a JPG at 600 dpi from a TIFF - it was 324KB. Then I downscaled it to 300 dpi and saved it as a PNG. Uncompressed it was just under 3MB. Compressed it was 1MB. A compressed 600 dpi PNG is over 2MB, uncompressed is 11.4MB.

The 600 dpi JPG looks much better at extreme magnification than the 300 dpi PNG. In fact, with JPG at 600 dpi, for any enlargement I need to make, I don't see any compression artifacting until I blow the thing up to about 200% - which means, for the size of images I plan to make from these things, I will never come even close to being able to detect the results of the JPG loss. My point is that the resolution has a much greater impact on image quality than the JPG loss, and, to a certain degree, you can offset the loss by adding resolution to your scan - but the resulting increase in file size will not be proportional to what it would be with a lossless format. For my purposes, I don't see much benefit to storing most of my images in TIFF or PNG unless I plan to do extreme enlargement/cropping.

I guess if I was an archive or library where the cost of storage was not a consideration, I would scan everything 600 dpi TIFF (PNG is an open standard but not as widely supported as TIFF and JPG from what I have seen). But I have over 10,000 scanned images that I need to send out on thumb-drives to relatives. I can't afford the storage (and inconvenience of dealing with multiple external hard drives - and backing them up) to scan everything lossless and then downscale it to send out copies. If I did, I would probably need to reduce the resolution of my scans. Based on my experience above, I would rather pay the price for the compression than use a lower resolution.

There is probably not a hard and fast rule here about what is best in every circumstance. But rather than going with the conventional wisdom that you should always use lossless formats, I decided to experiment a bit and come up with an approach that optimizes for my particular situation.

EDIT: I suppose the other thing I can say is that I rarely use screen captures to get images off the web. I usually right-click and save as to save it in the original form. Or, when in Ancestry viewing a census image I will use their SAVE TO COMPUTER option. When I'm screen capturing I'm usually trying to get a record of the text and layout of a web page - such as a modern abstract of a record on Ancestry.com. So, JPG works fine for that since I just want it to be legible but it doesn't have to be pretty.

Don

[sgtbob]

Re: Format Question

It's Command-shift-4 then drag through what you want to capture. It makes a camera shutter click and puts the file on your desktop.

This article tells how to change from PNG to JPG (although you have to issue a terminal command and "kill" a process. Not for the squeamish! But you only have to do it once.)

http://theturninggate.net/2012/08/change-screen-capture-file-format-on-mac-os-x/

A lot of people swear by Snag-It and other screen capture programs. I already have an image editor (PhotoShop) and can use the built-in screen capture described above and they work fine for my purposes.

Wow! Thanks for the command+shift+4 hint to capture a screen shot - its so easy. I had been using the 'Grab' function for a long time, so this will work also.

Bob

[Terry Medlar]

Re: Format Question

Wow! Thanks for the command+shift+4 hint to capture a screen shot - its so easy. I had been using the 'Grab' function for a long time, so this will work also.

Bob

I used to use the cmd, shift 4 and it was easy. Now it seems to put a pointer on my clipboard and when I click it is in Dropbox. What am I doing wrong?

[Bob White]

Re: Format Question

I used to use the cmd, shift 4 and it was easy. Now it seems to put a pointer on my clipboard and when I click it is in Dropbox. What am I doing wrong?

You very likely reassigned that key combination to do exactly what you describe. Check in System Pref > Keyboard under the Shortcuts tab. If you have reassigned, you could assign a different combination to the Dropbox action and the OS should default back to doing screenshots.

I don't use this shortcut or Grab unless I happen to be at someone else's Mac helping them and need a screenshot. There are a number of very good screenshot utilities that allow lots more options and the ability to add arrows, labels, icons, etc... My main actor is SnagIt. Another good one is SnapZ Pro.

[Frank Zwolinski]

Re: Format Question

Slightly off the point, but I checked out Snagit on the web, and then purchased it because it was supposed to do a "scrolling capture." Since several of the pages I want to "capture" are larger than my computer's window, I thought this was "just the trick," however I just cannot make it work and the tutorials don't seem to help me. Perhaps I have blinders on but I would like the advice of someone with experience using this software for this purpose.

If anyone would be willing to accept a call about this, please let me know and I will be happy to call you.

Thanks,
Frank
<fzwolinski@santarosa.edu>

[Susan Freas Rogers]

Re: Format Question

If anyone would be willing to accept a call about this, please let me know and I will be happy to call you.

Hi Frank, I'd be happy to talk to you about this, I've been using Snagit for years, and it's been invaluable for my genealogy work. I've even given presentations on it for our two local genealogy groups here in town. Yes, the scrolling capture can be glitchy and there are some remedies that usually work (though not always).

I'm not far from you (in relative terms), Grass Valley. You have my phone and we've talked, hope it works for you!
Susan