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PivotViewer: Trading Card Visibility

I'm developing a PivotViewer (Silverlight 5) control that makes use of Semantic Zoom. There are two trading card templates, a "small" template displaying a low-resolution image, and a "big" template displaying a higher-resolution version of the same image and some text.
The low-resolution images are bundled in the XAP file. I'd like to dynamically download and display a trading card's higher-resolution image when the high-res version of that template becomes visible. But the best I've been able to do thus far is downloading the image when the trading card is selected through SelectionChanged, as seen here:
http://www.beerolf.com/pivottest/SilverlightLoadTest.html
(When you click a trading card, you should see text saying "Big!!!" indicating that the high-res image is being used. If you zoom into a trading card before clicking it, the original image remains.)
This is okay, but I don't want to force users to click trading cards to see higher-resolution images. Is there any way to determine which trading cards are currently visible?

The trick with multiple templates is to get the sizing right.
In the example that you gave, the templates are loading fairly large since there are not that many of them. In a case like that, you are most likely going straight to the larger template.
I would put the source url of the high-res in your larger templates, so they will load automatically. Is there a reason you aren't doing this?

Overlay image with PNG as mask using .Net and Javascript

I have a project I am working on where the user can upload a frame image in PNG format. After they upload the frame they can upload a photo that will be placed behind the frame. The photo can be resized and moved so they can fit their photo into the frame. Once they are happy with their work, they can save their work.
The canvas is a fixed size on the client. This is an ASP.Net MVC4 application and we are using JavaScript / JQuery. I have only worked a little with the System.Drawing library and not sure how this will all fit together, yet. If this can be done easily in using just .Net and JavaScript / JQuery that would be great, but I am not opposed to using a 3rd party .Net library alongside JavaScript / JQuery.
UPDATE
I am goign share the step the user will go through to Resize, Move, and crop the image.
Step 1: The user loads the frame by clicking on some UI and it opens a popup with a working area of 432px x 348px. The frame is a PNG with a transparent center and outer edge. On that window will be an area for the user to upload an image. As you can see in figure 1, the image is loaded at 100% and goes past the window. The user can choose to move the image around and crop or move onto step 2.
Step 2: The user will move the image around to find the handles so they can resize the image. They can chose to crop at this point without resizing, as well, or move onto step 3.
Step 3: The user will resize the image and move it into place. Once they are finished they will crop the uploaded image.
Step 4: This is the final result after the data is sent to the server to be processed.

It can be done in pure .NET. No other libraries have to be used.
In order to add image uploading feature to Your application, take a look at the answer here: Upload Photo To MVC 4 Applications.
If You make user upload the image with a frame in png format with transparency support, You should be able to just draw one image on another, like in a sample code here (a gif is used there): http://www.daniweb.com/web-development/aspnet/threads/112667/how-to-overlay-two-images-in-c.
You can also support frames in other formats (like jpg or bmp), however, in order to support this scenario, You should manually choose which pixels to draw on the original image. One of the easiests solutions would be to make one of the colors a transparency key, so when a pixel is in this color, it won't be drawn in the resulting image. You can choose bright pink or another color that is rarely used (or even allow a user to choose it). It's still not very complex, buy it requires a little bit more code, some additional work to make it fast and a treshold to detect similar pixels in case of bad quality frame images.
If You want some help with the code, let me know.

What image format can c# load fastest?

this may seem like an odd question, and I don't know the formats of images so I'll just go ahead and ask...
I'm making a minesweeper game (relevant to different things too) which utilizes a grid of buttons, then I'm adding a sprite to the buttons using backgroundImage. If the grid is 9x9 it's fine. 15x15 it slows down and 30x30 you can visibly see each button being loaded.
That raises me to my question: Which image format would load fastest? Obviously, file size takes a part in the loading speed, however, I am enquiring as to if, say, a jpeg - with the same filesize as a gif - will load faster. or a bmp, png, etc.
I'm asking this as to see if I can get my grid to load faster using a different format.
Thanks!

You want an image format that paints faster. There's only one, the one whose pixel format directly matches the video adapter's setting so that the pixel data can be directly copied without needing format adjustments.
On most any modern machine, that's PixelFormat.Format32bppPArgb. It draws ten times faster than all the other ones.
You won't get that format when loading an image from a resource or a file, you have to create it.
Do note that this still won't give you stellar paint speed if every cell in the grid is a control. Particularly if it is a button, they are very expensive to draw since they support transparency effects. You'll only get ahead here if you draw the entire grid in one Paint event handler. Like the form's.
A completely different approach is to cover up the visible delays with this hack.

use the 8-bit PNG or GIF format and reduce the number of colors in the palette. Some image programs such as PhotoShop allow you to save the image for the web and fine-tune the image settings. By reducing the color palette from 256 to something like 32, you greatly reduce the size of the file. The less colors that the image has, the smaller the file size is going to be.
PNG has a similar feature called "Interlaced". You may want to turn this feature off so that the full image downloads quicker.
Because the 8-bit PNG and GIF formats have the potential to result in much smaller image files, try to keep this in mind when creating graphics and illustrations for your application. Try to keep the amount of colors to a minimum and use flat graphics instead of photographs. This way you can create images with palettes of 16 colors, keeping the file size extremely small and fast to load.
Best Regards

Are you reloading the image every time you paint a button? If so, there's your problem - solve it with a cache.
Are you painting the image at its native size? Runtime resampling can create a performance hit.

use PNG or GIF it's faster types of images

what is Image Processing?

I am going to Create an application where user can edit their pictures like color balance effect, gray sheet effect, invert effect , red eye fix etc.
My application will be quite resemble to Acdsee Software.
So i wanna know that can My application be called image Processing software ?
In my point of view Image Proccessing means playing with image's enhancing the image's.
Thanks In Advance

In electrical engineering and computer science, image processing is any form of signal processing for which the input is an image, such as a photograph or video frame; the output of image processing may be either an image or, a set of characteristics or parameters related to the image. Most image-processing techniques involve treating the image as a two-dimensional signal and applying standard signal-processing techniques to it.[1]
So, I think you can call your software a Image Processing Software, once it check what this definition propose.
[1] http://en.wikipedia.org/wiki/Image_processing

Yes, an application that does color balance, gray sheet effect, invert and red-eye fix, can reasonably be called image processing software. In fact, even a single one of those I would already call an image-processing algorithm.

Is there a more performant alternative to ImageList.Images.Add?

I have a winforms ImageList which contains 200 256x256 images.
When I add the images, 1 by one, half of the programs time spent on the Add method according to ANTS .NET profiler.
So the program takes 10 secs to launch and 5 is spent there. That is very slow in my opinion.
I implemented the same thing using ImageList.Images.AddRange. The result did not change.
Does anyone know any alternatives or optimizations to solve this? Is the WPF ImageList any faster? Is there a faster winforms ImageList?
EDIT:
foreach (string imageFile in images)
{
imageList.Images.Add(Image.FromFile(imageFile)); // takes pretty much all of program's execution time.
}

Have a look at the album and list views in PhotoSuru, one of Microsoft's WPF sample applications. They have a couple different thumbnail view screens that load pretty quickly (all the images are loaded asynchronously, and only the images necessary are loaded). And there's full source code to get you started if it's what you are looking for.
It not precisely like Picasa (they decided only to show full rows of photos instead of a partially covered row like Picasa), but by implementing your own virtualizing IScrollInfo panel (reasonably straightforward, and Ben Constable has a great series of posts on it), you should be able to get the performance you're looking for and the behaviour you want.
A final note: You might be doing this already (are your images stored as 256x256 pixel images?), but whenever you're trying to display image thumbnails, you'll want to avoid loading the full image. Reading 2 MB+ image files off of the disk just to render an entire screenful of 256x256 pixel thumbnails always has a bigger performance hit than reading an appropriately sized small thumbnail image instead. If you can, cache the thumbnails somewhere (like Windows and Picasa do), or at the very least, try to use the embedded thumbnails in any JPEG files you encounter.

Are you using a ListView for the UI part using that ImageList?
The general solution to these kind of problems is to only load some of the images, because only some of them are shown at a time, and then load the other as needed. ListView has a VirtualMode property for this kind of scenarios.
Loading and adding 200 images at once may be too much to do, you could load the first shown images and then use a background thread to load the others. Have a look at how Win7 display images, it shows some placeholder when you scroll and then, when the image is loaded it shows the real picture. Be warned that this is not a simple thing to do.

try my code here to scale-down your image and make a thumbnail out of it.

Yes it is. Load images to List<Image>. Then call ImageList.Images.AddRange(list).
List<Image> list = new List<Image>();
foreach (string imageFile in images)
{
list.Add(Image.FromFile(imageFile));
}
imageList.Images.AddRange(list.ToArray());