I am creating an application to give the functionality of overlay as in photoshop.
I have two images,
The background image on which the overlay would be added,
The Foreground image to which the filtration will be applied
Note: Both the images are in .jpeg format
I tried to use the Chroma Key effect, but it has some smoothness issues and not working properly on different color removal.
This is the image after applying the ChromaKey effect by removing black color
The above image has smoothness issues
There are images like this also when I try to remove its background color, it doesn't work properly
How can I achieve this functionality
Thanks!
Related
My requirement is to fill specific color on specific area of an image. But the image should be an image taken from iphone camera or photo gallery. For example, I could take a picture of me with a blue shirt, the app should allow me to change the color of the shirt to red.
Exactly the functionality of "Paint bucket" tool of the photoshop.
I found couple of approaches
1) Using MASKS with prepared images
color selected part of image on touch
Fill color on specific portion of image?
Scanline Flood Fill Algorithm
https://github.com/Chintan-Dave/UIImageScanlineFloodfill
2) Using GLPaint (Actually this is NOT the solution I am running after)
My question is,
Is it possible to color specific area of a image WITH OUT having MASKS or with generating masks for the image on run time?
Scanline Flood Fill Algorithm does that in to a certain level. But when it comes to real time images(like selfie images) it wont work correctly?
I have been designing an app with oCanvas.js. It's a really nice canvas library that makes it much easier to create an app that can create and manipulate images, but I ran into a snag when I was trying to implement image filters:
I need transparent backgrounds so that I can have multiple layers, each of which is represented by its own display object, rendered separately (meaning one at a time) on a hidden "staging" canvas. Immediately after being rendered, a layer is then drawn on top of the previous layers on the visible canvas, so that different image filters can be applied to each layer independently during render.
The issue I am having is that, when attempting to extract the image from an oCanvas object's canvasElement, the resulting images never have a transparent background. For example: Imagine I have a 50x50 canvas that has been oCanvas.create() processed, but has display: none; (this is used as the rendering canvas) and another canvas (same dimensions) without an oCanvas instance. I am trying to do something like this (Pseudocode):
visibleCanvas.getContext("2d").drawImage(MyOcanvasCore.canvasElement, 0, 0);
I have also tried using URL = MyOcanvasCore.canvasElement.toDataURL() and then having my visibleCanvas do a drawImage with src=url.
The images always transfer, but they have a white background, even though I specify background: "transparent" during canvas.create(). As such, they completely overwrite all previous layers.
Do you have any tips for me? Am I doing it wrong? I tried transferring stuff from one canvas to another using classic drawRect, drawImage, etc methods, and transparency was retained. That's why I believe it is either the library or my code.
I guess you are using the image format other than png.
You should have your image format in PNG which keeps all the details of every pixel >including transparency of pixels
and not a compressed format.
So just try keep your image in png format after edting them in some image editor and save > result as .png .
i wonder, how i could figure out if an image has a transparency effect applied. Is there any way in JavaScript or HTML5? I have a Base64-coded image. Is there a way to read out the transparency-information (alpha-channel). For example, if i load a PNG-Image, then convert it to base64, then drop it to html5-canvas, now how can i know if this has transparency-effect activated?
thanx alot
okyo
When you say 'drop it to html5-canvas', I assume you mean using an image element with the 'data:' URI scheme. Also, let's take it as given that you don't want to write javascript code to parse the image files.
You could do something like this pseudo-code:
create 2 off-screen canvases
color one opaque white and the other opaque black
draw the image on both of them
call getImageData on each canvas, using the image bounds
compare the image data
If the image has any transparent or partially-transparent pixels, then presumably the two canvases will end up at least a little different. One exception would be if the image has the transparency feature enabled but is entirely opaque anyway. Another would be if the non-opaque pixels are only very slightly transparent - not enough to alter a white or black background. But this technique would catch images where transparency is noticeable.
I've started using Fireworks to do prototypes, but now I need to code a prototype in HTML/CSS. I have all relevant image elements sliced, but the default behavior for Fireworks seems to be to export slides with any visible background elements embedded in the picture. E.g. When I export a logo I want the area around the logo to be transparent - I don't want the background behind the logo, which was located at a different layer.
Is it possible to export all elements with the transparency intact?
Copy your logo to a new document and export it. Lay it on top of your header graphics using CSS or maybe table if you are going that way. The point is if you see the background colors around the logo in your slice view, there is no way of exporting it transparently. The purpose of slicing is to export what you see in the sliced rectangle.
Make sure that there is no background in the image, either use the wand tool to delete the background or some other method and then make sure the images are exported as .png
Normally I'm using CALayer shadowRadius, but now I also need to use UIImage and apply shaped shadows to it based on the content in the image.
For example when I have a layer with text in it and I set a shadow, it works automatically on the text and not just on the rectangle of the layer.
In Photoshop this is known as "layer style" and it automatically works based on the shape of the image content.
I am afraid that I need to implement some Harvard-Stanford-MIT-NASA kind of hardcore logic to apply a shadow on a "shaped image", i.e. an image of an round icon where the areas around the icon are fully transparent.
I'm able to manipulate images on a per-pixel level as I'm doing this already to draw charts, so if there was an open-sourced implementation of some fantastic algorithms this would be fantastic. And if not: How does this basically work? My guess is I would "just" try to blur a grayscaled version of my image somehow and then overlay it with the non-blurred version.
My guess is I would "just" try to blur a grayscaled version of my image somehow and then overlay it with the non-blurred version.
That's pretty much it, actually. Except instead of blurring a greyscaled version of the image, blur a solid-colored version of the image (i.e. keep the alpha channel, but make all pixels black). Although CALayer's shadowing should do this already for you.
If your images are already composited onto a background (i.e. without real transparency), you have a harder problem as you first need to "remove" the background before you can have the shape of the object in order to generate the shadow.