Is there any sane way to work with bitmaps in WPF? I'd like similar functionality as System.Drawing.Bitmap: be able to load image from file and get and set the color of particular pixels.
I know about WriteableBitmap, but I don't want to work with Arrays of gods-know-what (I couldn't find that on MSDN), or pointers. I just want to read or write pixel, it shouldn't be that hard!
I also know that I can use Interop to work with System.Drawing.Bitmap in WPF, but that's not nice either.
Here's something on how to do get pixel info from a System.Windows.Media.Imaging.BitmapImage.
Although, if you'd prefer to work with a System.Drawing.Bitmap you might want to add a reference to System.Drawing.dll and use it instead.
Here's a somewhat-related forum post on image manipulation in WPF.
Related
I'm currently looking to achieve a gradient effect a bit like the rectangle in http://pjnicholson.com/Fireworks/fillgradients.htm
If I compromise a little I can get close to this using RadialGradientBrush... but is there any (not too painful) way to achieve the rectangular effect?
Use an ImageBrush instead and use this image (or a similar image generated using some image editor) for the background of your rectangle.
One solution a colleague and I came with was to derive a new Panel that used a WriteableBitmap as the source for its background.
The panel will give you the dimensions you need to make your WriteableBitmap. Using whatever algorithm you want you can fill it appropriately. In our case, we needed a radial or cone gradient, but the same concept applies.
Additionally, you can create several properties on your new control to specify the colors for the gradient. We adapted a LinearGradientBrush for our needs, but if you're working on just two colors, simple properties may suffice.
I don't have the code handy but will try to find it and post an update later. But the above should get you going.
I am using xlib.
I have an XImage structure filled with information from an XGetImage() call. Is there a popular method to get from XImage to something more meaningful.. namely PNG?
I have looked at libpng, but have heard from pretty much everyone that it's a beast to tame. Would this still be the recommended path to take?
See also How to save XImage as bitmap? though that person had the constraint that they couldn't use a library.
If you can use a library, Cairo is a good one that will do this for you I believe. It has PNG saving dealing with the libpng mess for you, and it has code to get the pixels from X. However, it may make it hard to get pixels from an XImage; it will want to get them from a window or pixmap. If you can just replace your XGetImage() with cairo, then it might work fine. The way you would do things roughly in cairo I think is:
create an Xlib surface pointed at your drawable
save to PNG http://cairographics.org/manual/cairo-PNG-Support.html
You could also use the Xlib surface as source to draw to an image surface, and then do other stuff with the image surface (scale or paint on it or whatever) if you wanted, before saving as PNG.
If you're using any kind of UI toolkit, it probably has code for this too, e.g. GTK+ has gdk_pixbuf_get_from_drawable() etc.
I need to render the value of the width or height of a 2d geometry object and the request is for it to not just be text, but somewhat like a dimension that would be a set of building plans. Something like this image...oops too new to post images...like this image that I googled -
http://www.archidigm.com/lounge/archdim/centerline_dim_1.gif
I have looked for something like this, but haven't been lucky in my search. I am fine with creating it, but thought that I would try to not reinvent the wheel if possible. Anyone know of a control or library out there that renders something like this?
This article looks really helpful: http://msdn.microsoft.com/en-us/library/bb613591.aspx. Although it talks about optimizing drawing, it gives mention to a lot of different classes you can use.
Specifically, take a look at the Drawing class: http://msdn.microsoft.com/en-us/library/system.windows.media.drawing.aspx#snippetGroup1
If you want the shapes to be interactive (because it seems like you are building a CAD-like application), the DrawingGroup might help. Check out this example: http://msdn.microsoft.com/en-us/library/system.windows.media.drawinggroup.aspx#snippetGroup
Also, DrawingGroup might be a good way to group the actual shape (for example, a wall in a building) and the ruler object that shows the dimensions.
I want to put an image on a button, but I want part of the image to be transparent. How do I do this?
Try the Image.OpacityMask property. You can give it a brush that specifies the region you want to be transparent.
EDIT: From MSDN:
There is no direct support for
color-keying a bitmap in WPF.
However, it is fairly easy to
implement on your own. Dwayne has
implemented a ColorKeyBitmap on his
blog:
http://blogs.msdn.com/dwayneneed/archive/2008/06/20/implementing-a-custom-bitmapsource.aspx
I believe it links to the code on
Codeplex as well. You could also
accomplish this simply by reading your
bitmap into system memory, iterating
through all the pixels and setting
their values yourself, and
constructing a new bitmap out of that
array.
Use a paint program (I use Paint.Net) to change the area you want transparent to an alha=0 color. Then save the image (mine was JPG) as a PNG. Seemed to work fine for me in the WPF Image control.
I'm developing a WinForms c# 3.0 application. Our designer created quite a lot of .ico files containing all the needed art. The choice of .ico was made because quite often, the same image is needed in several places in different dimensions.
Now, it seems .ico files are really annoying to use in visual studio. The only way to use those images seems to be through images list (which aren't supported by all controls).
Compared to other resources, you can't write this :
foo.Image = global::RFQHUB.RFQHUBClient.Properties.Resources.foo; // Cannot implicitly convert type 'System.Drawing.Icon' to 'System.Drawing.Image'
Here are the options I'm considering :
create ImageLists of all possible sizes referencing all my icons in my main window. Link these ImageLists from other windows and find a way to export Image objects from the ImageList when I can't use it directly ; since ImageList contains a Draw() method, this should probably be possible.
convert all the x.ico I've got in several x16.gif ...x48.gif, and use those through resources.
I'd be interested to know if some people have been successfully using .ico resources in a Winform application. In so, how did you set up things ?
ICO isn't quite an obsolete format, but it's close. It's still useful for your application icon, but for almost everything else, it's better to use an ImageList for each size that you need. And it's much faster to populate an ImageList from a bitmap that contains multiple images layed out in a grid.
You also want to use an Alpha channel transparency in your bitmaps to get the best result, so storing them as .PNG files in your resources is the best way to go, since PNG supports an alpha channel. ICO and GIF files support only single bit for transparency - every pixel is either fully opaque or fully transparent. An 8 bit alpha channel for transparency looks much nicer.
If you can send your artist back to the drawing board then you should do so, and have him/her do full anti-aliased images with alpha. If you can't, then I suggest that you write a small program to convert all of your icon files into bitmaps suitable for loading into ImageLists.
Convert the images into PNG. Point. Whoever decided to use .ico files to start with should get talked to in private - the argument holds no ground.