var qualityEncoder = Encoder.Quality; var quality = (long)<desired quality>; var ratio = new EncoderParameter(qualityEncoder, quality ); var codecParams = new EncoderParameters(1); codecParams.Param[0] = ratio; var jpegCodecInfo = <one of the codec infos from ImageCodecInfo.GetImageEncoders() with mime type = “image/jpeg”>; bmp.Save(fileName, jpegCodecInfo, codecParams); // Save to JPG
Here’s some algorithms to play with: Median or repeated box blur filter to obtain cartoonish color palette Edit: Bilateral filtering should suit your needs even better Min filter (zeroth percentile) to enhance some types of edges Color image segmentation using either small subcube or sphere in the RGB color cube Generic edge enhancement on segmented … Read more
The reason the rectangle doesn’t show up in the saved image is because you are not modifying the variable im, which stores the image data. The rectangle is simply a plot object displayed over the plotted image. You have to modify the image data itself. Typically, images read into MATLAB are loaded as an N-by-M-by-3 … Read more
Yes, there are faster ways to do this. Your simple loop spends most of the time in cache misses. This happends because you touch a lot of data at very different places in a tight loop. Even worse: Your memory locations are exactly a power of two apart. That’s a size where the cache performs … Read more
If you use OpenCV > 2.0 it is as easy as using namespace cv; Mat rotateImage(const Mat& source, double angle) { Point2f src_center(source.cols/2.0F, source.rows/2.0F); Mat rot_mat = getRotationMatrix2D(src_center, angle, 1.0); Mat dst; warpAffine(source, dst, rot_mat, source.size()); return dst; } Note: angle is in degrees, not radians. See the C++ interface documentation for more details and … Read more
To modify an image proportionally, simply only alter one of the width/height css properties, leave the other set to auto. image.style.width=”50%” image.style.height=”auto” This will ensure that its aspect ratio remains the same. Bear in mind that browsers tend to suck at resizing images nicely – you’ll probably find that your resized image looks horrible.
The best-known library is PIL. However if you are simply doing basic manipulation, you are probably better off with the Python bindings for ImageMagick, which will be a good deal more efficient than writing the transforms in Python.
You can use Queue to remove recursion from floodfill algorithm. Here are some basic ideas: Have a way to mark visited points At the beginning, queue the start point. While the queue is not empty, continue dequeuing its element. And with each element Fill its color and mark just-dequeued point as visited Enqueue unvisited adjacent … Read more
Here is working code… may help somebody public class ImageDemo extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(new Panel(this)); } class Panel extends View { private Bitmap mBitmap; private Canvas mCanvas; private Path mPath; private Paint mPaint; Bitmap bitmap; Canvas pcanvas; int x = 0; int y =0; int r =0; public … Read more
The Canvas documentation explicitly does not specify a scaling method – in my own tests it did indeed anti-alias the image quite badly in Firefox. The code below copies pixel by pixel from a source image (which must be from the same Origin or from a Data URI) and scales it by the specified factor. … Read more