Showing posts with label photo-viewer. Show all posts
Showing posts with label photo-viewer. Show all posts

Monday, March 19, 2012

Which Windows raw image viewer can only show jpeg, but on delete both raw and jpeg?

Question

I'm searching for an image viewer with the following features: (situation is, that both jpeg and raw are saved)

  • windows (7) support
  • when clicking through pictures only show jpeg
  • when deleting photo, delete both raw and jpeg
  • auto-rotate at EXIF-rotate attribute
  • freeware

At the moment I use Faststone Image viewer, which has all wished features except show only jpeg (if raw exists) and delete both raw and jpeg.

Asked by Chris

Answer

Check out this tool: FastPictureViewer

I'm not sure if there is a free version available but for those who are intrested in buying a viewer that's able to do this... Just take a look :)

Answered by Thomas Dekiere

Thursday, February 9, 2012

How can I link a specific 500px portfolio in Facebook with thumbnails in the correct order?

Question

I am sure this is simple and I am just missing something; How can I post a link to a specific 500px portfolio of mine so that the link others see displays the thumbnail images in the correct order or shows the first image in my portfolio.

If I just copy and paste the link to my portfolio, it adds all the images as thumbnails in some random order.

Asked by Jakub

Answer

Facebook is sort of a pain to work with for images, IME. The most reliable way to throw them clues seems to be the use of their open-graph meta tags. This post on wordpress.stackexchange.com is a pretty good place to start. I'm not positive I'm looking at the right 500px portfolio for you (the link in your profile is broken, I believe), but I'm not seeing any OG tags in there. Even with the use of OG tags, though, I'm not sure there's a way to specify order beyond just ordering the tags (and I'm not sure how well that's respected by FB).

At some point in 2012, I believe 500px is supposed to offer customizable portfolio themes (most likely for "awesome" customers only), but I have a feeling your best bet may be to just wait for them to get the meta tags sorted out themselves.

Answered by D. Lambert

Friday, January 27, 2012

Are “Windows Photo Viewer” rotations lossless?

Question

Can I rotate lossily compressed photos that I view in Windows Photo Viewer without worrying about losing even more information to compression?

Answer

If the dimensions of the image are multiples of 8 (or 16 if chroma subsampling is used) then the rotations are lossless. Otherwise it is not possible to rotate the image without recomputing the blocks i.e. recompressing the image, which is lossy.

The reason for this is that jpeg images are broken up into a series of 8x8 or 16x16 blocks which are compressed individually. Incomplete blocks are only allowed on the right edge and bottom edge. Thus is your image is not an exact multiple of 8/16 it will contain incomplete blocks, which will end up on the wrong edge after rotation.

I verified the above assertion using the version of Windows Photo Viewer that ships with Windows 7. I used two images of colour noise. One image was 256x256 i.e. both sizes multiples of 8. The other image was the same but cropped to 253x253 i.e. neither size was a multiple of 8. Here are the images:

256x256

253x253

I then performed four anti-clockwise rotations, closing photo viewer after each rotation to ensure the image was saved in it's rotated state.

256x256

253x253

There's no need to perform a subtraction to see the difference with the 253 pixel image, it's noticeably darker and muddier!

A diff on the other image looks like this:

i.e. the images are identical, the rotations were lossless.

Tuesday, October 18, 2011

What software shows the most accurate version of a photograph for web viewing?

Question

I have a photo (photo_A.jpg), taken on a post-sunset beach, for which I want to reduce some noise. I do so using the luminance noise reduction technique from Adobe Camera Raw, open the image in Photoshop CS5, and save another version (photo_B.jpg) of the photo. The settings used to save the JPEG were: maximum quality (12) and the Baseline("Standard") format option.

Now when I observe both the versions using Picasa 3, I see that there is quite considerable color loss in photo_B. But when I compare them using Windows Photo Gallery or even Photoshop CS5, I don't see any color loss!

In fact, the only change I see between A and B is the exact noise reduction that I'd hoped for. So, I decided to upload both the pics on Flickr and see what it looks like. And guess what... I see the same color loss for photo_B on Flickr as well.

As a result, I have the following questions:

  1. Should I trust Picasa more than Photoshop to 'view' my images?
  2. What would be the best software to view the images, so I can expect that that's exactly how they'll look online?
  3. Am I missing something very basic while saving the images from Photoshop?

I hardly dabble with color profiles etc. and hence have little knowledge about them.

Answer

Since you can't do anything about the color management of other people's monitors, the best you can do is:

  1. Make sure your own system is properly color managed (see ). That way, you are at least certain that you're starting from a known point. This is really worth doing even though it takes some effort and probably a small expense (which could perhaps be shared with a friend.) If you're hesitant to go down the whole rabbit hole, both Windows 7 and Mac OS X come with basic tools for visually winging it — better than nothing. (Or use http://displaycalibration.com/.)
  2. Work in the sRGB color space. I know this seems uncool given that there are wider-gamut spaces with names like "Adobe RGB" or "ProPhoto" (and pro must be better, right?), but I find it best to work in the space that is the target. That way, you don't get surprises due to gamut clipping or shifts when you go to make your final output. (See note below.)
  3. Save in sRGB. This is the defacto standard — that is, by industry agreement, it is the assumption that any uncalibrated setup should do a decent job of displaying sRGB images to a reasonable approximation of the original. Sometimes the approximation is awful enough to make color fanatics cringe, but that's the cruel reality of the world.
  4. And then, make sure you look at your images in various web browsers on as many different systems as you can to make sure they're okay. Or at least approximately okay. Uploading to Flickr and looking at it there is exactly the right thing to do, if you expect the photos to be viewed on Flickr as the final presentation. To answer the "what software" question directly, the answer is the software that will be used in the end — a web browser.

Oh, and in case it the above doesn't make it clear, my guess as to what's going on is that your JPEGs (either originally from the camera or from a setting in the RAW conversion) are using a color space other than sRGB — probably Adobe RGB, since that's the most common alternative. The programs where the photo looks as you expect understand how to properly deal with that, and the programs where it looks wrong are rendering the data as if it were sRGB.


Footnote: If you're worried about working in the constrained sRGB color space instead of a wider gamut, keep your RAW originals. Then, you can redo this decision later for a different output medium. There are good reasons for the other color spaces and I don't mean to disparage them or their use. They're just not what you want here.