i was wondering if there is a way to clear a text overlay using opencv. i nee to write text to the same area of the screen and it just writes over the initial overlay
You can draw a white rectangle at the place you want to write text.
cv::rectangle(image,topLeftPoint,bottomRightPoint,cv::Scalar(255,255,255),CV_FILLED);
Related
I'm trying to do some image recognition using Open CV. I want to detect the position of a dark rectangle in a game called Diablo 2.
After detecting the position of the rectangle, I will extract the text of that rectangle using OCR.
I've prepared some examples using Photoshop of where are those rectangles located.
On the left you can see the game screenshot, on the right I've pointed out the dark rectangles using a red rectangle, that's the place I want to detect using OpenCV.
Which OpenCV method should I use to detect those dark rectangles?
I'm not sure if Open CV is capable of doing this kind of pattern recognition, would be great if anyone can point me out how to do it.
How do I write text like this over a curve like bezier, bspline etc. using pygame or python 3?
If you know the angles you want to display the text at, you could create images for each letter and then use pygame.transform.rotate on the letter to create a new, rotated image.
Pygame text functions are limited to monochrome text rendering in a straightline, using the font's hinting.
Cairo (and PyCairo) however, offer heavy duty drawing and text rendering APIs -
so you probably will have to learn how make your curved text in Cairo, and transfer the cairo image to a Pygame surface for your game.
There is a wiki page on how to transfer images between both here: http://pygame.org/wiki/CairoPygame - I am not sure if Cairo's API alone contemplates curved text, but it can render SVG - so you can create your curved text in SVG, render it in cairo, and paste it in Pygame.
I downloaded a icon, and now i want to reset the color of it, but i'm not good at photoshop, i've set the color of it to be red, but there are to many edges and corners, please tell me how to remove those edges by using photoshop step by step, thanks a lot.
here is the icon i downloaded:
and this is my ugly one:
The best way to alter a single color like this on a simple image such as this is to alter the Hue and Saturation [CTRL / CMD + U]...
This allows you greater color control and keeps the anti-aliased edges of the image intact.
Most beginners alter colors like this by simply selecting the color with the wand, or using the paint bucket on the color. Unfortunately this usually does one of 2 things:
Makes the ragged edges that you saw.
Leaves a halo of the old color as an orphan.
I did this in a few seconds with that tool:
I have some .bmp files that have some color (maybe black) that is supposed to show as transparent when the graphic is displayed on top a form, so the form color comes through the transparent areas. But by default, when I put these images in an Image View, the black/transparent areas show up as BLACK!
I'm thinking I need to either:
- alter how the NSImageView shows the image, so that a certain color is transparent, or
- modify the .bmp files somehow to make that color suitable for transparency in an NSImageView
But I don't know enough about graphics files, transparency(alpha), NSImageView, nor the image editing tools. I'm trying to use Gimp, but...not sure what I'm doing yet. It seems like there is already a color that should be transparent in the current .bmp file.
I'm sure its something simple for setting NSImageView, or editing my file, or perhaps making a mask for the image, but I don't know how yet. I've looked at various filters in IB for NSImageView, but have not found where to set the transparent color, nor how to grab that color from the image file to make sure I use the correct value.
Thanks in advance for any assistance. (I tried to post some images, but because I'm new, I could not.)
Beau
I'm not a Cocoa developer, but in Gimp try adding an alpha channel to your image (a layer mask, perhaps) then saving as a 32-bit PNG image (with an alpha channel), then load that PNG directly into your NSImageView. If you want to make the black pixels transparent in Gimp use the magic-wand tool to select them (use magic-wand with 0 tolerance) and just delete the contents of the selection then save as a PNG directly.
World Map Images in Adobe Illustrator CS5
I have an image Map in illustrator CS5 which i want to save in GIF so as to reduce its size for web use. But when i save it, the map boundaries are having some white pixels all along the map boundaries of map.
I really dont know why has happened to it, but cant save it in Png-8, png-24 formate due to size constraint.
Any meaningful answer will be highly appreciate and thanks in advance.
Is your background a non-changable color? Maybe you can save the image with the same color as a background.
The problem is gifs don't support true transparency.
If this doesn't work can you provide the image you are trying to save (gif and png, I don't have AI right now)? Maybe there will be something I can do about the size or clearing the gif's edges.
transparent GIFs don't have an 8-bit alpha channel, like PNG does: a pixel in a GIF is either there, or it's not: if it's there, you can't see through it. This often means that an edge between transparent and non-transparent areas looks blocky.
There are two ways to deal with this... either use a PNG 24 (and the Illustrator Save for Web feature will help you to make it smaller), or in Illustrator create a background color layer behind your image before you export to GIF. If this background color layer is the same as the website you put the image on, the edges will blend nicely.