colormatrix

Android apply colorMatrix colorFilter on part of imageView with a mask

由 倖福魔咒の 提交于 2019-12-20 10:47:16
问题 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. 回答1: for given bitmap and mask: first create a temporary bitmap: bitmap = BitmapFactory.decodeResource(ctx

contrast with color matrix

由 倖福魔咒の 提交于 2019-12-13 12:22:34
问题 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

Clarification about how ColorMatrix transformations work

由 ⅰ亾dé卋堺 提交于 2019-12-12 08:38:57
问题 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

Subtract Blend Mode using ColorMatrixFilter in Android?

由 [亡魂溺海] 提交于 2019-12-12 07:39:07
问题 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 ]; 回答1: 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:

Rotate Hue using ImageAttributes in C#

由 我只是一个虾纸丫 提交于 2019-12-10 23:27:57
问题 How can I rotate the hue of an image using GDI+'s ImageAttributes (and presumably ColorMatrix )? Note that I want to rotate the hue, not tint the image. EDIT : By rotating the hue, I mean that each color in the image should be shifted to a different color, as opposed to making the entire image a shade of one color. For example, Original:http://www.codeguru.com/img/legacy/gdi/Tinter03.jpg Rotated: http://www.codeguru.com/img/legacy/gdi/Tinter15.jpg or http://www.codeguru.com/img/legacy/gdi

Binarize image before OCR scan

由 本小妞迷上赌 提交于 2019-12-10 19:25:28
问题 I have an name card scanner app to help in create new contacts which follows the following steps: User take a picture User crop the picture System shows user cropped image to confirm the crop System retrieve cropped picture and run OCR System takes OCR results and populate into the contacts fields (eg, Name, Phone number, Address, etc) User can edit and save contact. However. now I hope to increase the accuracy of the OCR process to produce better results for the OCR scan. I have heard of

How to use ColorMatrix in .NET to change Brightness, Color, Saturation, Hue

由 你离开我真会死。 提交于 2019-12-10 19:16:24
问题 I have a 'Bitmap' type containing some random bitmap data. I've written my own adjustments for Brightness, Color, Saturation, and Hue that act on each bit individually and, unsurprisingly, it's awful slow. In my research I've noticed that using matrices can be very fast in adjusting these. In addition, .NET has a ColorMatrix where you can apply the matrix effects when you DrawImage(). The matrix we set up looks like the following (from MSDN website): float[][] colorMatrixElements = { new

SVG feColorMatrix doesn't work in safari

由 给你一囗甜甜゛ 提交于 2019-12-07 10:39:06
问题 I have a fairly simple setup where I want to alter the color of the svg image by using an svg filter: <svg style="height: 0;"> <filter id="hover" color-interpolation-filters="sRGB" x="0" y="0" height="100%" width="100%"> <feColorMatrix type="matrix" values=" 0 0 0 0 0 0 0 0 0 0.68 0 0 0 0 0.94 0 0 0 1 0 " /> </filter> </svg> <img style="-webkit-filter: url('#hover'); filter: url('#hover');" src="https://upload.wikimedia.org/wikipedia/commons/8/81/Wikimedia-logo.svg" alt="" /> Please see the

SVG feColorMatrix doesn't work in safari

由 对着背影说爱祢 提交于 2019-12-05 13:09:56
I have a fairly simple setup where I want to alter the color of the svg image by using an svg filter: <svg style="height: 0;"> <filter id="hover" color-interpolation-filters="sRGB" x="0" y="0" height="100%" width="100%"> <feColorMatrix type="matrix" values=" 0 0 0 0 0 0 0 0 0 0.68 0 0 0 0 0.94 0 0 0 1 0 " /> </filter> </svg> <img style="-webkit-filter: url('#hover'); filter: url('#hover');" src="https://upload.wikimedia.org/wikipedia/commons/8/81/Wikimedia-logo.svg" alt="" /> Please see the attached codepen for details . It's working in firefox and chrome, but I can't seem to find the problem

Adjusting Lightness using ColorMatrix

由 人盡茶涼 提交于 2019-12-05 06:38:23
问题 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
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