I'm currently working on an application with the need to display large engineering drawings that can be 8800x6800 or larger. The requirements state that the user should be able to pan and zoom the image. Ideally, they'd like to be able to annotate the images as well. If you look at the Windows Photo Viewer, you'll see the performance and features I'm looking to emulate, minus the annotation part.
So far, I've tried a couple different approaches for displaying the images and none seem to offer the performance that I'm looking for. Either they take up a lot of memory or they're slow. These are the approaches I've taken:
Viewbox with the Image as a child. Memory usage is OK, but re-sizing the Viewbox is slow. I haven't tried zooming/panning with this approach yet because of that.
InkCanvas with the Image set either as the background or as a child. With this approach zooming/panning by way of ScaleTransform and TranslateTransform seemed so-so, but memory usage could be up in the 450-600 MB range.
This is my first foray into image manipulation with .NET/WPF and my knowledge on the subject is fairly limited. What are some best-practices for dealing with large images, especially with WPF? I've read that tiling the image (like deep zoom) can help, but was unsure on how to do this or if it's the best idea in my situation. Do you know of any resources that might help me understand this better?
By "tiling" if you mean splitting the image up into separate pieces and only displaying a small subset at once to improve performance, this would be called "virtualisation".
Microsoft has an excellent blog about virtualising items and even provides a reference implementation of a VirtualCanvas which you can use as the starting point for a virtualised control.
Link here: https://learn.microsoft.com/en-us/archive/blogs/jgoldb/virtualized-wpf-canvas
Note that this blog includes zoom and scale as part of the discussion as well as a discussion about smooth scrolling and pre-emptive loading of tiles for best UI responsiveness.
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When I upload an image, it is quite big some times, I have to create its thumbnail in a specific way.
What I want is if I declare the size of 96x69 for the thumbnail, those uploaded images which are scalable to this resolution should be scaled, and those uploaded images which are quite different in wxh, example 1000x1000, they should be cropped to maximum better scalability.
Is there any fast library or built in code as I have tried to do in my own way but it is not that perfect?
I strongly recommend ImageResizer which can be found freely on the Nuget. Basically, resizing images is a sophisticated procedure that may be included variety techniques such as cropping, scaling, resizing, moving, trimming, etc. that implementing each of these methods is not an easy job. Hence, it's better to use image-resizer.
you can use jquery for solving this problem. If its feasible in your project to do it client side.
Check these link here..
http://www.jqueryrain.com/demo/jquery-crop-image-plugin/
and
https://code.google.com/p/resize-crop/ this one is best and easiest i guess.
If you want to do it server side for some reason, then have a look on solution mentioned in this question.
Which free image resizing library can I use for resizing and probably serving images?
Hope this will solve your problem.
I was experiencing some performance issues when displaying a large number of images, I discovered the issue was that the full resolution image was being used when I really only needed an image less than 1/4 of the size. So I added a line in between BeginInit and EndInit to set the DecodePixelWidth to 200 which is the max width I will need in my layout. My performance was no longer an issue but some of the images are really small, definitely nowhere close to 200 pixels wide. Most of the images seemed to display correctly, and there doesn't seem to be any rhyme or reason to which are too small and which work correctly. I thought it might be due to differences in the original dimensions of the images but there was no pattern to the results. I tried bumping the width up to 600 which then allowed the offending images to display at the correct width of 200 but the performance then suffers.
At this point I am not even sure where to start looking, and would be really grateful for a kick in the right direction.
EDIT: Some more information below about the images and how I am using them.
Most of the images are around 1000X1500 although some have odd dimensions like 1000x1513. All of the images are JPEG. Currently each image is placed in a custom user control that I designed, nothing too fancy just a background around it with some text. Each user control is then placed in a grid, in its own row/column. The grid is inside a scrollviewer so the user can scroll through the list. This might not be the best way to accomplish what I am looking for but its what I came up with quickly and it works for the most part. Id be happy to switch to another method of display if it would accomplish what i want in an easier or more concise way.
The intended result is for a movie browsing app. There will be a scrollable list of movies, each represented as its own tile complete with title, movie poster, genre info, rating, and description. This list will be sortable on various items. The information about the movies is stored in a sql database on another machine. The images are originally stored on another machine but are copied locally to improve performance.
EDIT: I have been able to solve the issue by not using DecodePixelWidth and instead saving a copy of the image at the desired size, this has improved performance. Youngjae's recommendation of not using DecodePixelWidth along with his mention of using a virtualized list led me to the following set of articles on creating a Virtualized Wrap Panel which should solve any other performance issues. The article is for silverlight but from what I understand silverlight is basically a watered down version of wpf, if it works in silverlight it should work in wpf. It shouldn't be too difficult to convert it for my use.
Part 1 - MeasureOverride
Part 2 - ArrangeOverride
Part 3 - Animation
Part 4 - Virtualization
In MSDN link, you can find words as below.
The JPEG and Portable Network Graphics (PNG) codecs natively decode the image to the specified size; other codecs decode the image at its original size and scale the image to the desired size.
And, I recommend you NOT to use DecodePixelWidth for resizing purpose because of the above reason.
I don't know your original image sizes and formats, but isn't it enough to use with virtualized list and <Image Width="200" Stretch="Uniform">?
I need to speed up my image viewer, and wondering if I should be looking into creating my own DirectX control to do so.
My image viewer displays medical images. They can be pretty large. We're talking 55mb when it comes to mammography. The pixel data is 16bit greyscale stored in a ushort array. Without getting into the gory details, my current approach is loading the pixel data into an ImageSource, and using the WPF Image control.
I've never done anything with DirectX. Is it worth diving into it? Would it be any faster than the native WPF stuff? If so how significantly? Or, should I just forget about DirectX and look into areas where I can improve my current approach?
Before somebody says so, I know WPF utilize DirectX. I'm wondering If removing the WPF layer and writing the DirectX myself will improve performance.
I have some experience drawing multi-gigabyte satellite and chart imagery. Working with imagery around 55MB should probably work okay even without trying to optimize it too much. You haven't really given enough detail to recommend one alternative over the other, so I will give my opinion on the pros and cons.
Using 2D windows APIs will be the simplest to implement and should always be fast enough if you don't need to rotate and simply want to display an image and zoom and pan around. If you treat it as one large image the performance will not be as good when you zoom out if you are drawing with halftoning to give a nice smooth image. This is because it will effectively have to read all 55mb of image every time it draws.
To get around this performance issue you can make multiple bitmaps, effectively mip-mapping your image. As you zoom out you can pick the reduced resolution image closest to the resolution you are trying to draw . If you are not familiar with mip-mapping here is a Wikipedia link:
http://en.wikipedia.org/wiki/Mipmap
Implementing it with DirectX will be 10x as difficult. Different graphics hardware has different maximum texture sizes. Most likely you will need to break your image up in to multiple textures to draw and you will also have to keep track of render states, viewing matrices, etc.
However, if you do use DirectX, you can implement lots of real-time photo adjustments You can do real-time rotation by simply adjusting view matrices. You can do real-time contrast, brightness, gamma, and sharpness easily in a pixel shader.
There are two other API's I might suggest. If you are willing to limit yourself to Vista or later then Direct2D would be a little simpler than Direct3D. Also if you ever will need to implement it on a non-windows platform I would suggest using OpenGL instead. My current project is in Direct3D because a few years ago when we started it OpenGL was falling behind and I didn't forsee the popularity of Android devices. I now wish we had used OpenGL instead.
Try profiling to see where WPF is spending its time. Are you displaying the images at their native resolution? If not it might be worthwhile to do some preprocessing and create 1/2 resolution versions.
I'm creating a cad viewer which deals with very large image files and I am trying to optimise it for as high a framerate and low a memory footprint as possible.
It uses GDI+ for rendering onto a panel.
It's current flaw is with image rendering. Some of the files I'm using reference images which are particularly big (8000x8000 pixels). I've optimised the memory usage by only loading them when they become visible and disposing of them when they're not. This reduces the chance of the program running out of memory but prevents the images from being loaded and unloaded too often; however rendering the images themselves (context.DrawImage) still carries a very large overhead.
I'm now exploring ways of blitting the images into a smaller buffer of some sort, rendering this (generally much smaller) buffer, and then refreshing/rebuilding it when the zoom level changes significantly.
The problem is, I can't find any provision for this in GDI whatsoever. Can anyone suggest how I could achieve it?
I don't think GDI is designed for such high-speed updates of images. If you are trying to scroll the image, and tracking the mouse with each move, try to shift sections of the image and fill in the space opened up by the shift. Essentially reuse the tricks that programmers used when smoothly scrolling/panning graphics at a time when CPU's are slow and RAM is small.
If you're creating a new graphics application that needs a high framerate and are looking for suggestions, then I suggest abandoning GDI+ and using WPF. WPF uses hardware acceleration and supports retained-mode graphics; this has much better performance for less work than GDI+.
If there is some limitation that forbids WPF, please explain it in your question. This is relevant because such limitations can also impact GDI+ drawing.
GDI Binned in favour of Direct3D as 3D elements came into the equation anyway. Images turned into single thumbnails and larger tiles that are loaded in/out as required.
I faced a similar problem when developing my own GIS application. The best solution I found for this (even when using WPF) is to tile big images and display only the portions that are visible. This is being said, I would switch to WPF not only for the reasons given in the above answers but also for the good imaging support offered. See this link for more information
I'm trying to visualise a graph and allow people to play with it. I found the excellent Graph# library that can create an initial layout so that part is covered. Now I need to make a control that actually draws it and provides the necessary interactivity.
Graph# comes with a nice visualiser itself, however I don't like it because it is written in WPF (while my app is WinForms), and because I want to add some more interactivity options, which would require quite a remake of it anyway.
The graphs I'm drawing will routinely be pretty large, at about 100 vertices and the same amount of edges (the graphs will be trees 99% of time). That means that the resulting rendering can be up to 2000px by 2000px and even more. The users should be able to zoom in and out, scroll, highlight and drag vertices and edges, and get some popups with additional info when hovering the cursor above a vertex.
I'm worried that the standard System.Drawing might not be able to deliver a decent speed for this. I would like the dragging/zooming/scrolling operations to be smooth, and the popups should open with a little animation as well. Something like 20fps should be a necessity.
I know I can try to speed things up by pre-rendering a lot of the elements and keeping them as bitmaps in memory - but that would probably take up lots of RAM, and I'm still not sure if it would deliver the necessary performance.
What are your thoughts?
"Premature optimization is the root of all evil"
GDI+ can be great for your needs. Don't go and buy 3rd party libraries before you know you even need them.
I've done a thousand polygons on a 1000x800 pixel bitmap and redrawn it completely at over 100 frames per second, using just GDI+
That being said, if you have a lot of drawing to do, and your resolution is big.. Some of the 3rd party drawing libraries can go WAY beyond what managed GDI is capable of.
I recommend leaving Graph# alone, and just hosting it in your Windows Forms application.
The performance you will receive will be much better than trying to reimplement it in System.Drawing.
GDI+ will be plenty fast enough for what you're doing, especially if (as it sounds from your description) everything you're drawing is rectangles and vertical/horizontal lines. Polygons and non-linear shapes are a bit slower, but not much (the speed difference is partially dependent on the SmoothingMode of your Graphics object). Drawing cached Bitmaps with resizing is also quite fast, although it can slow down significantly if you use a high-quality InterpolationMode setting.
As a benchmark, I wrote a .Net Compact Framework GPS application for Windows Mobile that rendered about 10,000 lines on the screen in realtime. This only achieved a frame rate of a few frames per second, but the processing power on a Smartphone is, of course, way less than a modern PC.