So this may be a bit vague, but I'm having some issues. Basically, I am drawing my little ninja sprite (16x16px) and on 2 frames of his animation, he loses pixels on his headband. I have looked everywhere in an attempt to find an answer, but to no avail.
Original Sprite Sheet (Bugged frames are 4th row, 3rd and 4th frames):
After a little more investigation, it seems that the bugged pixels are due to the width of the sprite sheet. It almost seems random what pixels get messed up depending on the width. However, with a constant width, the messed up pixels are constant regardless of creating a new build or using an old one.
As you can see, the back of his headband is missing pixels. While it may not be game changing, it is very annoying and if anyone knows of a fix, that'd be great! Thanks guys!
My guess is that those pixels are magenta (255,0,255) which is automatically keyed out of the image as transparent by the SpriteTextureProcessor. If that is the case, change the pixels to be a slightly different color (255,1,255) or use the TextureProcessor for the content. You can do this in the properties window of the image file in your content project.
So a workaround I found is actually changing the size of the rectangle used to display the image. It was set to 100, setting it to 99 works and there is barely any visual difference.
Related
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.
I am developing a WPF C# video player with the MediaElement.
Some videos contain black bars at the top and bottom. I want to resize the picture i.e. to 120% so that no black bars are shown when I play these videos.
Now the question is how I can measure the size of the black bars. If i.e. a video has a height of 800 pixels I want to measure the height of the black bars. If there are 50 pixels black at the top and 50 pixels on the bottom then I will calculate that I have to resize the picture i.e. to 112%.
I guess I could make a screenshot of the video and then analyze that picture to find out how many black pixels are at the top and bottom (I have no idea how complicated that would be). But I guess and hope there is an easier way to do this. Any ideas?
This is the beginning of my answer: I just wrote a quick and dirty solution with the screenshot.
I used RenderTargetBitmap to create a screenshot with the height of the video but just 1 pixel wide. Then I used the BitmapSource.CopyPixels Method to extract the single pixels and then I looped through the pixels from top to bottom. It works, and it work fast enough for me (<30ms for the whole procedure).
I will publish the complete code when it’s done.
I am still interested if there is an easier way to do this. My own answer is just one answer but I am happy to accept something better as “the answer”.
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 currently using a semi-transparent WPF form with no border as a camera style device in a program of mine. However, when I access the position (top, left) and dimension (height, width) properties of the form, it would appear they are wrong.
The top property reported to be roughly 26 pixels higher than it actually is in relation to the desktop. IE if I put the forms top and left at (0,0) the properties will report (0, -26).
The height is also incorrect, reporting about 50-60 pixels shorter than it actually is.
Has anybody experienced this problem in the past and have a solution?
Regards,
Andy Hunt
if I understand correctly, this is no problem at all but the expected behavior.
WPF uses DPI-independent virtual units for measuring size and position, not actual pixels.
There are many sources like this explaining this.
If I understood the question wrong (its late and I am tired ;) could you provide a code sample illustrating the issue?
Andrej
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.