How to paint using brush with particular area... - ios

I want to fill each and every part with different colours like circle with other colour and each leave with different colour and stick with different colours. I have bunch of colours. You can fidn similar apps like Toonia Color book on apple app store...
I am unable to get bounds of particular part in image.
I searched a whole day before writing this question. Every one is saying just look for flood fill and Quick Fill algorithms but i am not able to solve this problem.

In Toonia Colorbook this is done using vector graphics and masks. Every shape is described as a bezier curve that masks a drawing layer.
check out CAShapeLayer and CALayer for further details

Related

Adding border to edges of opaque area of UIImage with a filter

Hello: Currently in my project, I'm using OBShapedButton to process touches on a lot of objects that overlap (it's a map with each territory its own separate object). Basically, this library prevents a touch from being processed on a transparent point on the given view.
I'm attempting to add a border effect to just the edges of the opaque part of the UIImage (and adding a semi-transparent overlay above that). Something to the effect of this:
Which can be simplified to this (example of one image):
I am currently using MGImageUtilities to color in the opaque parts of territories using this line:
[territory setImage:[[territory image] imageTintedWithColor:tint]];
The problem is that I'm not sure how to just color the borders (which can be any shape). I've looked at this link already, but haven't been able to come up with anything.
Thanks in advance for the help!
Terribly hacky, but use MGImageUtilities' UIImage+ProportionalFill with scale resizing to create a slightly larger image, UIImage+Tint to red, and stack below.
The library you are using doesn't actually specify a shape layer. It uses alpha values from the PNGs that you give it.
Could you use a different 'highlighted' or 'selected' PNG that adds the border effect you are looking for?
Otherwise, it you will have to generate a UIBezierPath from your PNG image, which sounds like a very computationally intensive operation. At that point, I might question whether this library meets your needs.

How to do Water color painting in iOS using CoreGraphics? [duplicate]

I have been working with OpenGL in iOS, and setting the colors with glColor4f(r,g,b,a) and then drawing my own color on a white UIImageView. I basically have a brush, which is then moved around my user's touch, and then it paints the color onto the canvas. But this color needs to be water paint (like smudged color)
Does anyone understand/knows how to get a water color like this app does, and how the background UIImageView has a texture on it?
https://itunes.apple.com/us/app/hello-watercolor/id539414526?mt=8
or checkout water paint in this. http://www.fiftythree.com/paper
I created a bounty on this as I am really having a hard time to grasp how to derive such smooth flowing colors out of the normal colors. Even if you guys point me in the right direction, or to some sample code on how I can get the effect of water-paint, it would be really helpful ^_^
And as a bonus, it would be also be helpful if you can point out to me how to get canvas on which it is painted on looks realistic, and blended with the paint? Does Blending/GLSL have to do with any of this?
Is there any sample project on this?
If you are still struggling with the basics of getting realistic looking water colors working, you may want to experiment/prototype in photoshop first.
http://www.zoepiel.com/tutorials/watercolor/ shows some very effective tricks for creating watercolor images with simple tools.
The most interesting one is to multiply a group of watercolor layers with a greyscale watercolor paper image. The texture of the paper makes some parts remain white, and other parts saturate with color, just like real watercolor.
Each layer remains 'wet' in the sense that the colors within it blend, but the layers are 'dry' with respect to each other.
She also explains some of her brush and blur settings and shows what they do.
Once you can produce the desired effect in photoshop, you'll have clear specifications of what you want to do and you'll be quite a bit closer to programming it out.
Looking at the examples you posted, it looks like they are using a simple Gaussian Blur with a radius of double your brush size. This may be an incomplete solution, but it's at least the first level.

Render water-paint in iOS

I have been working with OpenGL in iOS, and setting the colors with glColor4f(r,g,b,a) and then drawing my own color on a white UIImageView. I basically have a brush, which is then moved around my user's touch, and then it paints the color onto the canvas. But this color needs to be water paint (like smudged color)
Does anyone understand/knows how to get a water color like this app does, and how the background UIImageView has a texture on it?
https://itunes.apple.com/us/app/hello-watercolor/id539414526?mt=8
or checkout water paint in this. http://www.fiftythree.com/paper
I created a bounty on this as I am really having a hard time to grasp how to derive such smooth flowing colors out of the normal colors. Even if you guys point me in the right direction, or to some sample code on how I can get the effect of water-paint, it would be really helpful ^_^
And as a bonus, it would be also be helpful if you can point out to me how to get canvas on which it is painted on looks realistic, and blended with the paint? Does Blending/GLSL have to do with any of this?
Is there any sample project on this?
If you are still struggling with the basics of getting realistic looking water colors working, you may want to experiment/prototype in photoshop first.
http://www.zoepiel.com/tutorials/watercolor/ shows some very effective tricks for creating watercolor images with simple tools.
The most interesting one is to multiply a group of watercolor layers with a greyscale watercolor paper image. The texture of the paper makes some parts remain white, and other parts saturate with color, just like real watercolor.
Each layer remains 'wet' in the sense that the colors within it blend, but the layers are 'dry' with respect to each other.
She also explains some of her brush and blur settings and shows what they do.
Once you can produce the desired effect in photoshop, you'll have clear specifications of what you want to do and you'll be quite a bit closer to programming it out.
Looking at the examples you posted, it looks like they are using a simple Gaussian Blur with a radius of double your brush size. This may be an incomplete solution, but it's at least the first level.

iOS FloodFill : UIImage vs Core Graphics

I'm considering building an app that would make heavy use of a flood fill / paint bucket feature. The images I'd be coloring are simply like coloring book pages; white background, black borders. I'm debating which is better to use UIImage (by manipulating pixel data) or drawing the images with Core Graphics and changing the fill color on touch.
With UIImage, I'm unable to account for retina images properly; it destroys the image when I write the context into a new UIImage, but I can probably figure out. I open to tips though...
With CoreGraphics, I have no idea how to calculate which shape to fill when a user touches an area and then actually filling that area. I've looked but I have not turned up a successful search.
Overall, I believe the optimal solution is using CoreGraphics, since it'll be lighter overall and I won't have to keep several copies of the same image for different sizes.
Thoughts? Go easy on me! It's my first app and first SO question ;)
I'd suggest using Core Graphics.
Instead of images, define the shapes using CGPath or NSBezierPath, and use Core Graphics to stroke and/or fill the shapes. Filling shapes is then as easy as switching drawing mode from just stroking to stroking and filling.
Creating even more complex shapes is made much easier with the "PaintCode" app (which lets you draw and creates the path code for you).
As your first app, I would suggest something with a little less custom graphics fiddling, though.

Coloring Shapes in iOS app

We are building an iPad kids application in which a kid is requested to color different shapes with specific color. For example, consider an image with sky and trees , etc. all overlapping and a kid has selected a color for example "Blue" and then he taps the sky , the sky should turn to blue otherwise it should say "wrong color"
My questions are:
1- How to implement the coloring of the sky only with the selected color. We have implemented a Coco2d Floodfilling but it is too slow.
2- How to tie each part of the image with a specific right color. We suggested loading a fully colored image in a background layer and testing it at the tap .... BUT how to implement it.
Thanks
Are the shapes originally vectorial? If so, a solution would be to work directly with them as vectors, parsing them into CoreAnimation shapes.
You can give a try to SVGKit or get some inspiration from it. You'll get CAShapeLayers where you can change the fillColor property.
I believe that this way would be much more responsive (and the app size much more lighter) than doing tricks with images ;-)

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