I have a photo displayed on an iPhone. I would like to lower brightness of the photo at first, and when the user touches the photo, I would like to raise the brightness of the rectangular region near where the user touched, like this:
www.cottagearts.net/tut_images/tut_cropping_pse_06.jpg
Could anyone point me to a simple way of doing this?
While you can't actually adjust the brightness of the screen, you can put a semi-transparent image on the screen. I'd paint everywhere but where the user touched with an color that is black, but has X transparency, which is exactly what that image is showing that you linked to.
I'm no expert, but I've been trying to do something similar. You could implement this with layers. As Malfist suggested, you could make a black layer with a certain opacity and may the clicked part of it fully transparent or somesuch. Another option would be to do some image processing. I found an article here that I think will handle my highlighting issue:
http://arstechnica.com/apple/news/2009/03/iphone-dev-basic-image-processing-package.ars
Related
I updated this with an image of what I am trying to achieve, its a blur on a image which adds a touch of shading and even white on white is visible. I am basically working on putting buttons of various kinds on top of images and welcome's any and all assistance on best practices. I know facebook does this in some way as an app example.
To summarize what I am trying to achieve. I have an image that takes up the full screen and I would like to place a button on top of that image that does something like blur around it with padding so that it looks clean on top of the image. My button is a heart png, red outline with clear inside, and is represented as a square because of the irregular shape. I would like the heart to be on top of a circle that does something like blur the image so it can always be seen.
I found a number of similar solutions to this problem using UIBlurEffect but nothing that specifically addresses the "square image" and how I would control making the blur circle larger/smaller in terms of the padding around the square. I tinkered with creating a UIView that was transparent, placing a circle with a blur into there and then adding the button with their centers aligned but this seems like an incorrect approach and wasn't quite working. I suspect that for people with expertise this is something where I just need to have the correct usage of the UIBlurEffect.
I've been searching for that many time ago and I can't find a solution. I have a animated label that crosses the screen of the iPhone (like the title of a song does in the Music app.Well, I'd like to add the "fade in/out" effect like the music app has. The easy solution is open Photoshop and create this simple image and then add it up to the label. Well, under the label I have an image with black backgroud. The image can be zoomed in and then the image with the fade in/out effect can be seen, and it doesn't look well. Is there any possibility to do this programatically? Thanks
PD: if there's another possibility rather than doing this programatically, I'll apreciate the answer as well.
Edit: Here's the image capture of the problem
I'll approach it in a non-programming way.
The image reference you gave us for the Music app you seem to be emulating has a different gradient than the one you drew in the second image.
If you notice in the image, the gradient has not fully completed its transition from clear to black before the words are cut off. I would say in photoshop run the gradient from clear to 80% alpha black and then draw a 100% alpha black rectangle to finish it off as per image. The white is just showing you what it looks like without the black background.
Now as for the zooming. Correct me if I am wrong, but it sounds like you want a viewing window for the image so that once you have zoomed into it, it will fade to either side, but still be viewable/movable in the center. This means that the image has to be zoom-able, but once you have zoomed the "fade in/out" should not be zoom-able.
Just make sure you aren't scaling the fader by keeping it separate from the scrollView of your background image.
I want to implement the UI feature as in the image attached. The image is an screen shot form a Siemens App that is in App store. Here the bright portion can be rotated like wheel. I have gone through the link
http://www.raywenderlich.com/9864/how-to-create-a-rotating-wheel-control-with-uikit.
but I am not able to implement the feature as in image.
Following is the link to download the Siemens app.
http://itunes.apple.com/us/app/siemens/id452698392?mt=8
The simplest approach I can think of is to use two images. One would have the green and white detail display and one would be gray with a slight circular gradient, a lot of transparency, and a fully transparent segment.
The gray image would go on top and handle touch movement by rotating and taps according to its last stop position.
I need to change the color of the iPhone screen when i touch on it. The only thing i need to do is to change the color of the area where i am touching. if i am placing a star on the screen as touch then only that area color will be changed.
Any idea about this?
Take a look at some of the Graphics and Animation iPhone SDK Samples - there are samples there that show how to paint with different colours and other samples of how to use user input.
You guys helped so much with my last question, I figured I'd give you a shot at another. I have written an app with a theme that uses a dark blue glassy background and white / gray text and labels. The textfields in my app have clearcolor backgrounds and white texts and everything shows up very well. My only concern is that when you hold down a touch in a text box to get the magnification loupe, of course the white text shows up on a white background... which you can not read. Anybody got any ideas on how to implement a usable loupe here?
Unfortunately, the only "public" way I know how to change the loupe background is by setting textField.backgroundColor
I assume that since you're setting your backgrounds as clearColor, the magnifier defaults to white background, so the only way is to set your backgroundColor as something not clear.
I'm also assuming that since you did mention that you set your backgrounds a clear, that having it not be clear is not an option. So two ways I can think up in my mind about how to get around this is:
Assuming that the magnification lopue gets its background color by calling the backgroundColor implementation (and not some other obscure private API method): override the backgroundColor method and return a solid color.
Create your own loupe (probably not feasible)
I figured out a simple work around that achieved the desired effect. I also went through the full process of making my own loupe but since there is clear documentation on making your own loupe (see kiyoshi's answer), and this other method is ridiculously simple, I decided to document it here. It is basically just faking the clear background so that the white text shows up in the loupe. The background I am using for the view looks like blue smoke on a darker blue background:
alt text http://img231.imageshack.us/img231/9835/beforestatex.jpg
I took a screenshot of the simulator with the textfield visible and a black background so it would show up better:
alt text http://img193.imageshack.us/img193/9023/blackfieldx.jpg
Then I took that screenshot and made it semi transparent in photoshop, and overlayed my original background image to find exactly where the textfield appeared on the background:
alt text http://img266.imageshack.us/img266/9493/transparencyfullscreenx.jpg
Then I copied the exact pixels that would be used as the background of the textfield into a new PNG and saved that and set it as the the background image:
alt text http://img41.imageshack.us/img41/3450/textboxback.png
forwardToField.backgroundColor = [UIColor colorWithPatternImage: [UIImage imageNamed:#"textboxback.png"]];
Keep in mind that the image will be repeated as a pattern within the loupe... so if you don't want to see the edges, simply make sure your textfield is larger than the loupe height and width.
Before:
alt text http://img196.imageshack.us/img196/2672/beforex.jpg
After:
alt text http://img23.imageshack.us/img23/2182/afterxd.jpg
I hope this helps somebody out there!
Actually its pretty feasible to create your own loop. Haven't tried subitting to apple yet so don't know how they feel about it.
Basic idea is override touches, use a timer to see how long the user has been touching the screen. The loupe is just a UIView that grabs as an image the view behind it and magnifies it.
Check out this article from Craftymind here
The article has you cache the entire image behind which is definitely faster, for rendering the loupe, but if you have stuff (i.e. textFields) that are constantly changing I've been able to render the loope image real-time without too much of a performance hit.