colormatrix

Hi I want to implement contrast filter in my application like this link or this contrast but with color matrix and track bar for value I already found color matrix for it float c = mytrackbar.value * 0.01f //maxTrackbarValue = 100, minTrackbarValue = -100 float t = 0.01f; cmPicture = new ColorMatrix(new float[][] { new float[] {c,0,0,0,0}, new float[] {0,c,0,0,0}, new float[] {0,0,c,0,0}, new float[] {0,0,0,1,0}, new float[] {t,t,t,0,1} }); but the result is very different. I try to change 0.01f in ~c~ and 0.01f in ~t~ value but it only gives result like brightness (ex : c = mytrackbar.value *

I'm trying to adjust the lightness of an image (You can see this option in Photoshop when trying to adjust the Hue, also lightness and brightness are two different features) using ColorMatrix but am lost on which values to change to achive this. Currently I'm able to change the Hue using this code public static void adjustHue(ColorMatrix cm, float value) { value = cleanValue(value, 180f) / 180f * (float) Math.PI; if (value == 0) { return; } float cosVal = (float) Math.cos(value); float sinVal = (float) Math.sin(value); float lumR = 0.213f; float lumG = 0.715f; float lumB = 0.072f; float[] mat

I'm doing some work on an image processing app (for fun) and am struggling to fully understand how ColorMatrix transformations work. I get the basics of linear/affine transformations, and can get by just fine by replicating examples online, but I'd like to fully grasp why something works instead of just being satisfied that it works. For example, doing a simple transformation on an image to produce its negative (each color is converted to its respective complimentary) uses the following matrix: [-1, 0, 0, 0, 0] [0, -1, 0, 0, 0] [0, 0, -1, 0, 0] [0, 0, 0, 1, 0] [1, 1, 1, 0, 1] I understand that

I have the following ColorMatrixFilter. But I want to use it as a mask for Subtract-Blend mode, instead of using it directly. How do I go about achieving this? ColorMatrix: colorMatrix[ 0.393, 0.7689999, 0.18899999, 0, 0, 0.349, 0.6859999, 0.16799999, 0, 0, 0.272, 0.5339999, 0.13099999, 0, 0, 0, 0, 0, 1, 0 ]; Long story short There is no subtract blending out of the box in Android. However you can achieve desired color blending using OpenGL. Here is the gist, that you can use like this: BlendingFilterUtil.subtractMatrixColorFilter(bitmap, new float[]{ 0.393f, 0.7689999f, 0.18899999f, 0, 0, 0

I want to change the brightness on certain part of an image. I know how to use ColorMatrix to change the brightness(or hue) of an image. But it will be applied to the whole image. I have a mask file (black and white image). I want to apply the brightness change only on the the white part of that mask.How to do this in Android? Below is a mask image and the result I want to get. for given bitmap and mask: first create a temporary bitmap: bitmap = BitmapFactory.decodeResource(ctx.getResources(), R.drawable.bitmap); mask = BitmapFactory.decodeResource(ctx.getResources(), R.drawable.mask); float[]