rgb

问题 I have a requirement for converting and saving an image in CMYK format. When i have uploaded an image of RGB format, then i need to convert it to CMYK. Is it possible in .Net? Thanks 回答1: As others mentioned .NET does not natively support image colorspace adjustments. However, ImageMagick is excellent free software suite that will alow you to do this using the -colorspace or -profile option. The .NET library that will allow you to tap into ImageMagick is conveniently named ImageMagick.NET, it

问题 I have the following method that gets a rgb value and classifies it using a smaller palette: private static int roundToNearestColor( int rgb, int nrColors ) { int red = ( rgb >> 16 ) & 0xFF; int green = ( rgb >> 8 ) & 0xFF; int blue = ( rgb & 0xFF ); red = red - ( red % nrColors ); green = green - ( green % nrColors ); blue = blue - ( blue % nrColors ); return 0xFF000000 | ( red << 16 ) | ( green << 8 ) | ( blue ); } The code that annoys me is red = red - ( red % nrColors ); green = green - (

问题 Suppose I have a class RainbowColorsMapper with the constructor RainbowColorsMapper(int n) , where n>=2. Now I want to have continuous mapping of rainbow colors from red to violet which I get using the method mapper.getColor(int number) where low values correspond to red end, and high near n to violet end. If n = 2, mapper.getColor(0) returns most left color of the spectrum (near red), and mapper.getColor(1) returns the most right color. Same with bigger n with automatic scaling. My question:

问题 I am using the below code to extract RGB values from images, sometimes this works, however on certain files (seemingly where the Stride is not divisible by the width of the bitmap) it is returning mixed up values: Dim rect As New Rectangle(0, 0, bmp.Width, bmp.Height) Dim bmpData As System.Drawing.Imaging.BitmapData = bmp.LockBits(rect, Imaging.ImageLockMode.ReadOnly, Imaging.PixelFormat.Format24bppRgb) Dim ptr As IntPtr = bmpData.Scan0 Dim cols As New List(Of Color) Dim bytes As Integer =

问题 I am currently trying to develop a video player on Android, but am struggling with color formats. Context: I extract and decode a video through the standard combinaison of MediaExtractor/MediaCodec . Because I need the extracted frames to be available as OpenGLES textures (RGB) , I setup my decoder ( MediaCodec ) so that it feeds an external GLES texture ( GL_TEXTURE_EXTERNAL_OES ) through a SurfaceTexture. I know the data output by my HW decoder is in the NV12 ( YUV420SemiPlanar ) format,

问题 By calling getRGB(int x, int y) with a BufferedImage object, one gets a single, negative number. How can I convert three different values (a red, a green, and a blue) into this single, negative number? 回答1: Using the Color class: new Color(r, g, b).getRGB() 回答2: BufferedImage ends up delegating to java.awt.image.ColorModel which uses the following code: public int getRGB(Object inData) { return (getAlpha(inData) << 24) | (getRed(inData) << 16) | (getGreen(inData) << 8) | (getBlue(inData) << 0

问题 Looking at the PNG specification, it appears that the PNG pixel data chunk starts with IDAT and ends with IEND (slightly clearer explanation here). In the middle are values that don't make sense to make sense to me. How can I get usable RGB values from this, without using any libraries (ie from the raw binary file)? As an example, I made a 2x2px image with 4 black rgb(0,0,0) pixels in Photoshop: Here's the resulting data (in the raw binary input, the hex values, and the human-readable ASCII):

问题 I'm having an issue plotting an RGB image using Python's Basemap module with latitude and longitude data. Now, I am able to make the plots that I want, but the problem is how slow it is, since it is able to plot single channel data much faster than the RGB data, and in general, plotting RGB images on their own is also fast. Since I have lat/lon data, that is where things get complicated. I've checked out the solution to this problem: How to plot an irregular spaced RGB image using python and

问题 I have different RGB values in a 260000 * 3 dimension array. I wan to sort these colors in ascending or descending order (it does not matter which) so that similar colors are closer. What's the most efficient way to do this? 回答1: Example: First we start with the regular Jet colormap: %# sample image mapped to Jet colormap I = repmat(1:100, 100, 1); C = jet(100); figure subplot(211), imagesc(I), colormap(C) subplot(212), rgbplot(C) First we shuffle the colors. Then we try to recover the

问题 I'm using the following script to save images on a folder, but there is one image that shows this message "the image cannot be displayed because it contains errors". I think the problem is something called cmyk and rgb on the image, but when searching on the web for a way so convert cmyk to rgb using php I can't find an example of how to do this. Here is one of example: http://offshootinc.com/blog/2008/10/24/using-the-imagick-class-to-convert-a-cmyk-jpeg-to-rgb/ but I don't undestand how to