I am taking photos from a webcam in my Cocoa application and I would like to zoom in on the centre of the image I receive. I start by receiving a CIImage and eventually save an NSImage.
How would I go about zooming in on either of these objects?
“Zoom” means a couple of things. You'll need at least to crop the image, and you may want to scale up. Or you may want to reserve scaling for display only.
CGImage
To crop it, use a CICrop filter.
To scale it, use either a CILanczosScaleTransform filter or a CIAffineTransform filter.
To crop and scale it, use both filters. Simply pass the output of the crop as the input of the scale.
NSImage
Crop and scale are the same operation here. You'll need to create a new, empty NSImage of the desired size (whether it's the size of the source crop if you won't zoom or an increased size if you will zoom), lock focus on it, draw the crop rectangle from the source image into the bounding rectangle of the destination image, and unlock focus.
If the destination rectangle is not the same size as the source (crop) rectangle, it will scale; if they are the same size, it will simply copy or composite pixel-to-pixel.
Related
This is my set up. I have 2 layers with transparency (I don't know if transparency matters here). Layers are the same size, 5x7 inches. Each layer has their image (say I draw a square on it and a circle on the other).
I want to resize ONLY the square.
The problem is when I scale the square I end up either scaling both, the circle AND the square, equally and they retain their layer size, or BOTH layers are rezise and no longer 5x7 inches. I've tried 'Tools-Transform-Scale' and 'Image-Resize canvas or image', but I can't find the tool to just resize ONE of the images.
Any ideas what I'm doing wrong?
Thanks
What you want is the Scale tool, and it will resize only the active layer if it is in Scale: layer mode (you seem to have it in Scale: image mode)(*).
Otherwise, to clear up things:
Image > Canvas size changes the size of the canvas, but nothing is stretched/compressed, the layers retain their size or are extended with transparency or white.
Image > Scale image scales everything in the image (layers, channels, paths...)
(*) Also,if what you apply a transform such as Scale to an item that has the chainlink, the same transform will be applied to all other chainlinked items (other layers, but also paths).
I have a viewer with a perspective camera. I know the size of the viewer and the pixel ratio. I have several sprites in my scene that use the .sizeAttenuation property to never change size.
With all of this, I want to be able to set the scale of the sprite instances to, for example, be 20px x 20px. Is that possible? Is there a known conversion from pixels to sprite scale?
What I am experiencing now is that the sprites will change size depending on the viewer size. I wish to know how to resize them when the viewer changes so they are consistently the same size.
thanks!
I've created an image in Photoshop to be used as a sprite in Unity and everything works fine while the sprite is scaled at X: 1; Y: 1.
The problem starts when I scale the image up as the border of the image stretches out with the rest of the image. Is there any way to scale an image from its centre or to ignore the image's border when it's scaled?
Here's the example now that I am able to show it:
The rectangle on top is the original image without being scaled up or down and the rectangle on the bottom is scaled at X:5, Y:0.5 but the borders are stretched.
I think that the borders are stretched because it's part of the image and when it's being scaled, the image (including the borders) is just being stretched.
Is there any way to stretch the sprite image but by ignoring the borders?
Are you trying to scale the image and keep the original ratio?
If so, here are the steps:
Hope this helps. Please let me know if you were trying to do something else.
You can use a sliced sprite. The center of the image is scaled to fit the control rectangle but the borders maintain their sizes regardless of the scaling. Check out the Unity doc here: Unity - Manual: Image
I'd like to be able to set a lock screen image that did not scale to take up the entire lock screen. This is causing a lot of issues with cutting off parts of the image either horizontally or vertically. If I have a WriteableBitmap version of my image, and either the height or width (whichever is larger) is scaled to be either the screen height or width, then how might I over lay that image on top of another image that is the page size to make the image become a 'full screen' image. I am thinking that this would mimic a 'screenshot', and therefore the lock screen would not try to scale the image (Even though there would be some blank background on part of the newly created image where the original did not show up).
As an example, if I'm trying to adapt a picture from PhotoChooserTask to overlay on a default image of 768x1280, where the 768x1280 will always remain in portrait orientation exactly as the lock screen does, regardless of the PhotoChooserTask image result's dimensions, how can I always make this fit inside the 768x1280?
I have been looking to dynamically scale a image map with coordinates to a div, so when re-sizing a window occurs the map and all coordinates are scaled accordingly.
any suggestions on how to do this?
i think this may work
http://blog.outsharked.com/p/image-map-resizer.html
but with the alternate option of :enter a bounding area and the map will be clipped to within that area.
my question then is how do i establish a bounding area, will it scale dynamically to that whole area?
This jQuery plugin works great for scaling and rescaling image maps on the fly. You can call this once, and it will take care of all image maps on the page. It will even rescale an image map if something happens that changes an image's dimensions.
https://github.com/stowball/jQuery-rwdImageMaps.
If you weren't just using the div to solve the image map scaling problem, you could put a blank image (a completely transparent .gif or .png) in your div with the image map applied to it and set its width and height to 100%.