How to manipulate images at the pixel level in C#
If you want speed, then LockBits. See here for a good walkthrough by Bob Powell. If you just want to edit a few, then GetPixel/SetPixel should do what you want.
image-manipulation
Javascript Image Resize
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.
Merge Image using Javascript
You can use JavaScript to ‘merge’ them into one canvas, and convert that canvas to image. var c=document.getElementById(“myCanvas”); var ctx=c.getContext(“2d”); var imageObj1 = new Image(); var imageObj2 = new Image(); imageObj1.src = “1.png” imageObj1.onload = function() { ctx.drawImage(imageObj1, 0, 0, 328, 526); imageObj2.src = “2.png”; imageObj2.onload = function() { ctx.drawImage(imageObj2, 15, 85, 300, 300); var … Read more
Imagemagick – Resize images to 25px height and aspect ratio
You can do all that with ImageMagick. You’re question is not very specific, so here’s a quick cheat sheet of command examples that may help you: # resize image to width 25, keeping aspect ratio convert -geometry 25x src/image1.png out/image1.png # resize image to height 25, keeping aspect ratio convert -geometry x25 src/image1.png out/image1.png # … Read more
Bmp to jpg/png in C#
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
Command line batch image cropping tool
In Linux you can use mogrify -crop {Width}x{Height}+{X}+{Y} +repage image.png for CLI image manipulation
PIL how to scale text size in relation to the size of the image
You could just increment the font size until you find a fit. font.getsize() is the function that tells you how large the rendered text is. from PIL import ImageFont, ImageDraw, Image image = Image.open(‘hsvwheel.png’) draw = ImageDraw.Draw(image) txt = “Hello World” fontsize = 1 # starting font size # portion of image width you want … Read more
Rounded Corners on UIImage
Here is an even easier method that is available in iPhone 3.0 and up. Every View-based object has an associated layer. Each layer can have a corner radius set, this will give you just what you want: UIImageView * roundedView = [[UIImageView alloc] initWithImage: [UIImage imageNamed:@”wood.jpg”]]; // Get the Layer of any view CALayer * … Read more
Can I access ImageMagick API with Python?
I would recommend using Wand (explanations follows). I was looking for proper binding to ImageMagick library, that would: work error/problem free be regularly maintained and up to date allow nice objective Python But indeed python API (binding) has too many different (mostly discontinued) versions. After reading a nice historical overview by Benjamin Schweizer it has … Read more
How to cartoon-ify an image programmatically?
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