how to animate some portion of images? - iphone

I am implementing fun application.In which i want to animate some area(portion) of images.
I dont know how it possible.If u have any idea then please help me.

If you're looking to animate a portion of an image you could just create a smaller animation and put it at the right relative location inside a larger image.
If you want to know how to animate images in general, that's a different question entirely.

Related

Make fix size round button as image in iphone sdk

I am developing an application in which I need to round button as image (as I uploaded).
It Show two corner are straight and the rest is in round shape. I tried withmybutton.layer.cornerRadius but make round whole image. I also tried to just make custom button but it leave extra space in button around image i need to fix size button as image show.
Please help me. Thanks in advance. Happy Day.
Here is a one good tutorial on this:
http://iphonedevelopment.blogspot.in/2010/03/irregularly-shaped-uibuttons.html
you can download code from here
https://github.com/ole/OBShapedButton
Hope this helps
An alternate but not really a good one first add an imageView add this particular image over it than add an custom invisible button over the image by adjusting size of the button it will not cover the whole image though but still it will work fine...actually i did use this approach in one of my app :p
OBShapedButton might help. It's an open source UIButton subclass optimized for non-rectangular button shapes. If it still doesn't work, making your own buttons isn't that difficult either. Use a UIView and handle touches within the view. For eg, in touchesMoved:, set the active image and in touchesEnded:, handle the click event!

Fade Image to Transparent in iOS

I am just starting out with iOS development. I'm trying to determine if this is possible in iOS and I'm new enough that I don't know what to search for, so please excuse my ignorance.
I'm going to be saving a few images in the application and the primary image will fade over another image like so:
Image A will still need to be a solid image, so my question "Is it possible to create a gradient mask that only fades for 50px from the bottom (transparent) of an image?"
Sorry if this is a basic question and since I don't know where to start I don't have any code to request help on. Any help would be appreciated! :)
Yes, it is definitely possible.
You will need to draw the images in a CGContext. Basically you would first draw image b first then draw image 'a' with an alpha mask using CGImageCreateWithMask.
It is very straight forward. See here for an example.

iPhone hide portion of image in UIScrollView

I am brand new to iPhone app development. I am trying to create an image reader using UIScrollView. I need to focus a portion of an image and hide the rest. Till now I am only able to focus required part of an image but have no clue how to hide the rest. I had a suggestion that, I need to add four views at top, bottom, left and right. I need to hide those as per requirement. But, I was able to go no where with the suggestion. Can you please tell me how can I implement the functionality?
I don't understand what you really want to do. But if you think putting for views above I might suggest you use mask image for the same. Use alpha component.
Atlast I was successful in hiding part of an image. I used four views with background color and resized them according to the portion I need to display.

Modifying, coloring and dragging pre-existing images iPhone application

I am developing an iphone application which would let me modify the image by dragging other images over its top along with functionality that would let me choose a specific color from the image and replace it with some other color shades i choose. If anyone has some clue like how to actually implement it or some code, that would be great help for me to proceed in right direction
Thanks in advance :)
If you just want to overlay images, you can simply drag UIImageViews around and position them within the view hierarchy such that the appropriate images are overlaid one on top of the other.
For generating a new image out of those composited images, you may want to use something like CGContextDrawImage() within a UIView subclass's -drawRect: method or in a custom CGContext. You can also refer to these similar questions:
How can we combine images and get image object from this two images in iphone apps
Combining images
As far as selectively replacing a specific color within a UIImage, that's a commonly asked question here:
In a UIImage (or its derivatives), how can I replace one color with another?
How to make one color transparent on a UIImage?

How to implement image masking

IN scrolllview there is one image with zooming facility.And behind the scrollview there is round image.now i want to masking.I have tried but not working.Can anybudy give me advice.
Typically masks go in front of the image you are trying to reshape.