I am trying to generate a video from the screenshots taken from a specific UIVIew. This view have an AVPlayer subview and also a canvas subview(in which we can draw shapes). Just tried the normal way of UIGraphicsGetImageFromCurrentImageContext and the screenshot was black. I think its because the video is rendered in GPU.
So I tried to take a screenshot of a GLKView to which the above two subviews were added. But still its giving the GLKView background colour as images. Referred the below two links for my purpose.
Tried adding glkview as in this post.
Taking screenshot from a GLKView
Am I going the right way? If yes, Please help me to understand what I am missing.
OR
Is there anyother better way to do this? AVAssetImageGenerater is not at all suitable for my requirement and so I cant use it too.
AVAssetImageGenerater is not at all suitable for my requirement and so
I cant use it too.
What is the reason for this i don't know but by using AVAssetImageGenerater it is possible to take snap of the video and draw the snap image over the screenshot image is easy as you know the frame of the black part.
See below post to put a UIImage over another UIImage.
Draw another image on a UIImage
Related
I'm trying to achieve a sort of dynamic UIView masking effect. Here is a sketch:
So as you can see, I'm trying to create a UIView that can effectively cut through an image to reveal the image behind it. I already know how to return an image with a mask statically, however I would like the "revealer" to be draggable (I'll use pan gesture) and live.
Does anyone have any ideas or starting points on how to achieve this? Thanks
(NOTE: My demo says White layer, but I'd actually like to show another image or photo).
masking an image is not that difficult.
This link shows the basics.
http://iosdevelopertips.com/cocoa/how-to-mask-an-image.html
But personally I think i would make 2 UIImage views and crop the content of the draggable UIView. I'm not sure but I would expect that clipping and panning the second image will be less computationally expensive then applying the mask and will get you a better frame rate.
So I would do: UIImageView of the full image. A UIView on top of it with a white and some transparency setting to make it look white, then a UIImageView with the image either places or cropped so that only the correct section is showing.
I am creating an application in which i am displaying image view with image and processing brightness on the image using slider. I want that brightness should be done only on the selected part of image and not on the entire image.
I want the brightness should be processed only on the central part of the image without using openGl Image processing.
Please help me to solve this problem. Hey guys Please help me its important for me.
There are several ways to accomplish this. One is to overide the drawRect: UIView method and use a mask. Another is to draw the bitmap yourself in a CGContext. Yet another is with OpenGL.
What have you tried?
I have numerous photos in portrait and landscape format. I want to be able to display a "crop" of the photo in a UIImageView on the iphone. If the picture is in landscape format I want it to resize to fit the frame, if it is in portrait format I need it to resize to fit the width, and then be cropped at the top and bottom. As if there is a "window" over the image - so it looks like a landscape picture.
It would be even better if this could be a UIButton - although I am aware that I can use touchesBegan and such on images to make it behave like a button if needs be.
Thanks for any help you can give me.
Thanks
Tom
In an ImageView, you can change the View Mode to Aspect Fill. It will give you the right scaling/cropping you want.
For interactions, you can use a Custom button with no drawing at all (no Title, no Image, no Background) with the same size as your ImageView. That would be safe with regards to the image aspect. I've tried similar stuff using the button's Background or Image properties, it can have some undesired effects (I've ran into a resizing issue on iOS 3.1.3 for instance).
1°) To Crop the Image, try to add a method to UIImage class to do it (you can google it without problem, or even on StackOverFlow)
2°) To add a "window" over your image, just add an UIImageView over your image wich has transparency. It should work ;-)
3°) To know when an image is touched, you can use "touchesBegan" to detect which image were selected. But I think it's the last of your problems ^^
What you cant to achieve isn't so hard, just to it step by step !
If you want more help in one step, say it. But I can't code it all for you ;-)
Good Luck
I need your help to know how to create an iPhone application to show a photo with SCRATCH OUT EFFECT.
Something like the effect in this flash tutorial
http://www.tutorial5.com/content/view/115/46/
Please help.
Thanks.
You can have a look at the following post on how to create a blurred image effect, I don't think it's the best & fasted method, but it might get you started:
UIImage blur
You can implement the scratch out effect by using CoreGraphics.
Subclass UIView for the scratchable image.
Draw the scratchable image, use a mask to cut out the parts of the image that gets "scratched".
Each time the user scratches the image, make it so the mask and the image gets updated.
Full code example on github
I have a UIImage.
I have an EAGLView in my app, which is a derivative of the GLPaint ("Shake Me!") sample program.
The UIImage is full-screen (320x480.) Actually, it's a screen-capture of the EAGLView's image from earlier in the program (like in this question.)
I'd like to set the layer-contents of the EAGLView to the image, and then continue drawing on top of that.
Hints? Pointers to sample code? Docs to read?
Thanks!
It turns out that EAGLViews can be stacked just like UIViews (and they can be intermixed), with transparency, so things were much easier than I was trying to make them.