Cocoa API Image Manipulation - objective-c

Is there any way to do simple image manipulation like adjusting brightness, contrast, exposure, etc. using Cocoa? Something like NSImage?

You want Core Image, I think.

If you want to present UI to allow the user to make these kinds of modifications, look at ImageKit.

Have you had a look at Core Image?

I'd check out the CoreImage FunHouse example. It pretty much shows you how to use most of what CoreImage can do.

Related

How to achieve this image distortion effect in iOS?

I'm building an iphone photo app. I don't know how to achieve this kind of effect on an image:
When the user drags a finger across the arrow, I want the image to be distorted accordingly. How can I achieve this? Is there any framework that makes this process simple?
Thank you.
No clue about iOS, but the look reminds me of a thin-plate spline warp. It's quite easy to implement in OpenGL, a quick Google search for example code returns plenty of hits.
From the sound of it I think your looking for the CoreImage framework. Look into the various distortion effects...in particular CIBumpDistortionLinear.
I don't have any code so check out this tutorial and read up on CoreImage.

Image processing - How detect array similar colors from a image on ios

I want to create a area of similar colors when user touches into a point on imageview. Who knows library or technique to resolve problems for ios.
Original image link:
http://cannshine.com/images/1.jpg
After touched by user, link:
http://cannshine.com/images/2.jpg
Please helping, thanks!
It looks to me like you want to create a magic wand tool, correct? I can't help you come up with a way to handle this and I don't know of any libraries that can select a group of like-colored pixels based on tolerance, but there is this article here I found. It covers implementing a magic wand tool using Objective-C. I found it in the answer to this similar question on SO.

webite mockup using photoshop

Ive been asked to create a website mock-up using Photoshop, but I'm not sure what size to use for my canvas.
Please could you help me about that? or give me an advice?
This is a hard question as mostly websites are adaptive. From my experience I would say the height doesn't really matter if you allow scrolling, otherways I would take 700px for height. The width should be no more then 1200px.
I'd simply suggest to stick with some grid framework, eg. 960.gs: http://960.gs/
You'll get a PSD grid to fit your design into and also CSS framework which you can use later for website coding.
For a more up to date grid framework I suggest http://unsemantic.com/ since it allows for a responsive grid.

Image Processing in iPhone

Actually I am adding Image Processing Feature in my iPhone Application It should do Brightness, Contrast, Sharpen, Exposure....
But i am not able to Find any article/Tutorial on the Internet. Will you please help me to find any tutorial or tell me how can i implement the iPhone View Based Application.
I have found 1 link http://www.iphonedevsdk.com/forum/iphone-sdk-development/10094-adjust-image-brightness-contrast-fly.html its worked also for Brightness but its not working on iPad.
So Suggest something that i can start with my Image Processing Logic.
Thanks
Rick Jackson
I personally like the approach in the GLImageProcessing project from Apple's sample code. Check it out.
There are a few libraries that support image processing in Quartz. There are even a few categories on UIImage to do some basic stuff.
The following are a few examples:
https://github.com/esilverberg/ios-image-filters
https://github.com/cmkilger/CKImageAdditions
http://code.google.com/p/simple-iphone-image-processing/
But as said before by #Felz those libraries are slow because they use the quartz codebase, which isn't that fast (for example: changing the saturation of an image with a resolution of 1024x1024 might take up to 4 to 8 seconds, depending on which device your using).
If your project is iOS 5 or higher then you should definitely consider using CoreImage
You can try GPUImage framework created by Brad Larson. It includes awesome image filters and also easy to use.

Using an nsimage as a "green screen"

Is it possible for me to take use an image as a green screen type thing like in photo booth where it takes the background out?
Yes, although exactly what you mean by “green screen” will affect the specific answer. Chroma-keying will require a custom CIFilter, as I don't believe Core Image comes with such a filter and I know NSImage by itself doesn't support it.