grayscale

I have a grayscale image ("lena" actually) which I want to experiment with. I got it as a 512x512 PNG file with 216 shades of gray. What happens is, when I read it with Java ImageIO, like that: String name = args[0]; File fi = new File(name); BufferedImage img = ImageIO.read(fi); I get a BufferedImage with only 154 colours ! I only realized this, cause my processed images which looked sallow, lacking deep black. Even more irritating, when I use XnView convert the PNG to a GIF, which is a lossless procedure in this case, read the GIF with above code, I get all 216 colours in my BufferedImage.

I use the following code to turn color image to grayscale image. The resulting image is gray, but too dark. Can I change the opacity of it? (not sure if the term "opacity" is the right word for it) + (UIImage *)convertImageToGrayScale: (UIImage*) image { // Create image rectangle with current image width/height CGRect imageRect = CGRectMake(0, 0, image.size.width, image.size.height); // Grayscale color space CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray(); // Create bitmap content with current image size and grayscale colorspace CGContextRef context = CGBitmapContextCreate(nil,

I am trying to find a recipe for producing a a blurred grayscale UIImage from a color PNG and alpha. There are recipes out there in ObjC but MonoTouch does not bind the CGRect functions so not sure how to do this. Any ideas? Here is one ObjC example of grayscale: (UIImage *)convertImageToGrayScale:(UIImage *)image { // Create image rectangle with current image width/height CGRect imageRect = CGRectMake(0, 0, image.size.width, image.size.height); // Grayscale color space CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray(); // Create bitmap content with current image size and grayscale

I want to open two png image files and display them side by side for visual comparison. I have this code for opening one png file (which I got from unutbu on stackoverflow.com): import numpy as np import pylab import matplotlib.cm as cm import Image fname='file.png' image=Image.open(fname).convert("L") arr=np.asarray(image) pylab.imshow(arr,cmap=cm.Greys_r) pylab.title('title') pylab.show() Is there a way to modify this code to open and display 2 png files side by side with their own titles? The following works for me (you can comment/uncomment the lines in the code to change the layout of the

Closed . This question needs details or clarity . It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post . Closed 5 years ago . I want to convert grayscale data to colored image using C#. I try 2D and convert 1D data and show bitmap, but I want to show Colored image. The built in graphics and drawings function from the .NET framework do not support working with Grayscale images. I did the same thing to display a gray image as a heatmap with false colors. In my case I used the library Emgu.CV This is some example code I

I need to be able to convert 8-bit or 16-bit grayscale pixel data into a file format that the .NET framework can support. The data I have available is the width, height, orientation (bottom-left) and the pixel format as 4096 shades of gray (12-bit resolution) packed in 2 bytes per pixel. So for example each pixel ranges from 0 to 4096, and each pixel is 2 bytes. I have already tried using PixelFormat.Format16bppGrayScale with the Bitmap constructor, and it throws a GDI+ exception. Everything I have read says that this format is not supported and that MSDN is wrong. I want to convert this pixel