I have a png that's size 150x100 , and I set the UI image to the same, but it makes a bunch of extra space around it (that can be interacted with). How do I fix this?
Image of Problem: https://imgur.com/a/2ILXY1t
Unity isn't adding extra space. The image itself HAS that space.
There are options to crop out the alpha space in Unity by using the sprite editor, but by my experience i prefer using a proper Image editor like Gimp. using one is the best way to handle your image assets.
To crop out the extra space you just have to reduce the canvas size.
Well, first you could check (in Unity) wether your Image has its property Preserve Aspect set to True.
You could click Set Native Size which is right below it, so the 'box' around your image will take it's size.
Edit: Nevermind the first two. I do not know why i thought they could solve it, i looked at your image again and i, too, think there are transparent pixels above and below it. So you should try this:
Then you could check whether your picture has any transparent pixels around it, using an image editor. If it has, you would need to cut them out.
Related
I have no experience with images. I have to detect simple object in static image. For example I have image like:
I want to detect edges and remove background. Just to compare them.
Something like this.
Do u have any solutions of this problem? Images have often white backgrounds.
I've just thought about detect edges, and take everything what they contains.
To segment out the shoe-
Anadptive Threshold to remove the smooth changing background.
Sobelx, which removes the apparent background line, which i assume is
common for images of this setup.
dilate, closing operation to separate out the shoe.
Find contours, bounding box etc as per your choice.
Do an additional threshold if you want to remove the shadow at the bottom.
I want to set an image to have a transparent background, but I do not want to replace all pixels of a specific colour with transparency.
To be more specific, the image is a thumbnail image for a folder, obtained via IShellItemImageFactory.GetImage. This gives me a Bitmap, as displayed in Windows Explorer thumbnail view, but the background is solid white.
I can use Bitmap.MakeTransparent on it, and that will work in most cases, but in any cases where the thumbnail image contains white itself (for example, a folder that contains images, which include white colours).
Incidently, this is the first time in over 10 years as a developer that, after googling my question, I have not found an answer anywhere, and I've actually had to ask it myself. (I think that means I just levelled up! Yippee, I am now a level 2 developer...)
Use flood-fill algorithm to fill pixels of the same color from the OUTSIDE as you need it. It is something similar to magic wand in photoshop.
http://en.wikipedia.org/wiki/Flood_fill
What I would do is flood-fill with some obscure color (Magenta always does it for me), then replace that color with transparent (I don't know if flood filling with transparent pixels is feasible).
So what you're getting from IShellItemImageFactory.GetImage is a composite image that contains the original image on a white background? I suspect the white background is there if the image doesn't have the same aspect ratio as the thumbnail size. For example, if you ask for a 96x96 thumbnail of a 640x480 image, there's going to be some white space at top and bottom.
If that's the case, you have a problem. You can't differentiate between white pixels that are contained in the image, and white pixels that are added by GetImage.
There are a few things you could do. You could load the image and resize it yourself. That's probably the easiest. You'd want to maintain your own thumbnail cache then.
Or you could examine the image returned by GetImage to look for white space on the sides. Basically, if every pixel on a row (or column) is white, then make that row (or column) transparent. It's a little more complicated than that (the NBA logo, for example). But that's essentially what you'd want to do.
I'm writing a paint application. User must be able to move with all objects after it's painted or edited. I have a brush and erase tool, so user can erase all or any part of object painted with brush. So I made an object DrawBrush that holds a System.Drawing.Region made from GraphicsPath.
But I don't know how to size it. I need to change size in every direction separately on mouse move (for example only to left)
can someone help me?
I'm able to do anything with this object (moving), but no sizing...
A region is like a fence - it simply marks out the boundary of an area. It does not "contain" any graphics, so resizing a region will have no direct/visible effect.
If you wish to be able to move or resize portions of a bitmap image within your editor, you will need to copy a piece of your main image (as specified by your region) into a temporary Bitmap. Then you can draw the tempoary bitmap back to your main image (in a different location and/or at a different size).
If you wish to be able to draw multiple objects in your painting program, and then edit them (move them around and resize them) independently later, then you will need to store each of them in a separate bitmap object and composite them together to display the final image on screen or save it to a flat bitmap format. If you don't keep all the shapes separately like this, you will lose too much information and you won't be able to edit them later.
Before you try to work out write the code to do this, you may need to think about the design of your editor - what does it need to do, and how will you achieve it? How is your "document" going to be described? (A single bitmap? many small bitmaps that are drawn at different locations? Vector paths?). If you write code before you understand how you will represent the document, you're likely to paint yourself into a corner (sorry about the pun) and get totally stuck.
In normal C# it is easy to draw to a bitmap using the Grpahics.DrawString() method. Silverlight seems to have done away with Bitmap objects and Graphics is no longer available either. So...How am I meant to manipulate/create a bitmap when using Silverlight? If it helps, I am using Silverlight 3.
Let me tell you what I am doing. I am being given a template, basically a pre-rendered image. The user is then able to select from multiple images and enter the deisred text. I then render it to the image, adjusting size etc... within bounds and centering it in the pre-defined area of the image. If I can calculate the size (as in the MeasureString method) and then draw the string (as in the Graphics.DrawString method) that would be fine. The real question, no matter why I want to be able to do this, is can it be done?
The question is: why do you want to? Why not just use a TextBlock?
If you are trying to dynamically generate an image, use standard Silverlight/WPF controls (including TextBlock) and render them to a WritableBitmap.
Edit:
Ok, you've updated and expanded, which gives me more to go on. Unfortunately, you're not going to like the answer. First, keep in mind that Silverlight and WPF in general are vector based, and intended to be used as such. Although the Canvas allows you to do pseudo-pixel manipulations, you cannot be nearly as pixel-accurate as old-school GDI. This is a factor of your medium. If you absolutely have to measure things the way you want to measure them, I suggest you build your images on a remote server and transmit them to your Silverlight app.
You can calculate the size on-screen of the text rendered via a TextBlock using the ActualWidth and ActualHeight properties. But it only works on an already rendered control. Something like MeasureString is simply not available in Silverlight. Based on your description of your app, some user interaction could accomplish what you want. The user selects the image, enters the text, and is shown a preview. The user can then adjust the width and height of the various text areas until satisfied, at which point you can take a snapshot using the render method I liked to above.
The following may work, its a bit nebulous because I haven't tried yet myself.
The object you are looking for is the WritableBitmap.
You create a Visual tree, for example create your self a Grid or Canvas (you're not adding this to the UI). Add to it the selected image and a TextBlock positioned and sized as you prefer.
Create a new WritableBitmap either of a specific size or using the selected image to initialize it.
Use the WritableBitmap Render method passing the above root Grid or Canvas to it.
Now you have a bitmap which you should able to use to do whatever its you needed to do that required all this hoop jumping in the first place.
So here are the details (I am using C# BTW):
I receive a 32bpp image (JPEG compressed) from a server. At some point, I would like to use the Palette property of a bitmap to color over-saturated pixels (brightness > 240) red. To do so, I need to get the image into an indexed format.
I have tried converting the image to a GIF, but I get quality loss. I have tried creating a new bitmap in an index format by these methods:
// causes a "Parameter not valid" error
Bitmap indexed = new Bitmap(orig.Width, orig.Height, PixelFormat.Indexed)
// no error, but the resulting image is black due to information loss I assume
Bitmap indexed = new Bitmap(orig.Width, orig.Height, PixelFormat.Format8bppIndexed)
I am at a loss now. The data in this image is changed constantly by the user, so I don't want to manually set pixels that have a brightness > 240 if I can avoid it. If I can set the palette once when the image is created, my work is done. If I am going about this the wrong way to begin with please let me know.
EDIT: Thanks guys, here is some more detail on what I am attempting to accomplish.
We are scanning a tissue slide at high resolution (pathology application). I write the interface to the actual scanner. We use a line-scan camera. To test the line rate of the camera, the user scans a very small portion and looks at the image.
The image is displayed next to a track bar. When the user moves the track bar (adjusting line rate), I change the overall intensity of the image in an attempt to model what it would look like at the new line rate. I do this using an ImageAttributes and ColorMatrix object currently.
When the user adjusts the track bar, I adjust the matrix. This does not give me per pixel information, but the performance is very nice. I could use LockBits and some unsafe code here, but I would rather not rewrite it if possible. When the new image is created, I would like for all pixels with a brightness value of > 240 to be colored red. I was thinking that defining a palette for the bitmap up front would be a clean way of doing this.
Going from 32bpp to 8bpp indexed will almost always result in quality loss, unless the original image has less than 256 colors total.
Can you create another image that is a overlay with the affected pixels red, then show both of those?
Since you are going for brightness > 240, you can convert the overlay to grayscale first, then to indexed to get the overbright pixels.
You don't specify what you are doing with it once you have tagged the offenders, so I don't know if that will work.
Sounds like something you could do easily with a pixel shader. Even very early shader models would support something as easy as this.
The question is however:
Can you include shader support in your application without too much hastle?
Do you know shader programming?
EDIT:
You probably don't have a 3D context where you can do stuff like this =/
I was mostly just airing my thoughts.
Manipulating the picture pixel by pixel should be doable in real-time with a single CPU shouldn't it?
If not, look into GPGPU programming and Open CL.
EDIT AGAIN:
If you gave some more details about what the app actually does we might help a bit more? For example, if you're making a web-app none of my tips would make sense.
Thanks for the help everyone. It seems that this can be solved using the ImageAttributes class and simply setting a color remap table.
ColorMap[] maps = new ColorMap[someNum]
// add mappings
imageAttrs.SetRemapTable(maps);
Thanks for the help again, at least I learned something.