Android changes the image saturation, brightness, and contrast.

Colormatrix is used.

Java code:

Package COM. figo. imgedit; import Java. io. filenotfoundexception; import android. app. activity; import android. graphics. bitmap; import android. graphics. bitmap. config; import android. graphics. bitmapfactory; import android. graphics. canvas; import android. graphics. colormatrix; import android. graphics. colormatrixcolorfilter; import android. graphics. paint; import android.net. uri; import android. OS. bundle; import Andro Id. util. log; import android. widget. imageview; import android. widget. seekbar; import android. widget. seekbar. onseekbarchangelistener; public class imgeditactivity extends activity {/** called when the activity is first created. */private bitmap srcbitmap, dstbitmap; private string pathname = "/sdcard/testimg.jpg"; private imageview dstimage = NULL; private seekbar saturationseekbar = NULL; private seekbar B Rightnessseekbar = NULL; private seekbar contrastseekbar = NULL; private int imgheight, imgwidth; public static final int picture = 0; public static final int max_width = 240; public static final int max_height = 240; private URI imageuri; @ overridepublic void oncreate (bundle savedinstancestate) {super. oncreate (savedinstancestate); setcontentview (R. layout. main); dstimage = (imageview) findviewbyid (R. id. DST Imageview); saturationseekbar = (seekbar) findviewbyid (R. id. saturationseekbar); brightnessseekbar = (seekbar) findviewbyid (R. id. brightnessseekbar); contrastseekbar = (seekbar) findviewbyid (R. id. contrastseekbar); srcbitmap = bitmapfactory. decodefile (pathname); dstimage. setimagebitmap (srcbitmap); imgheight = srcbitmap. getheight (); imgwidth = srcbitmap. getwidth (); dstbitmap = bitmap. createbitmap (imgwidth, Im Gheight, config. argb_8888); saturationseekbar. setonseekbarchangelistener (New onseekbarchangelistener () {// This method is triggered when the slider position of the drag bar changes (seekbar arg0, int progress, Boolean fromuser) {// create a variable bitmap area of the same size to draw bitmap BMP = bitmap. createbitmap (imgwidth, imgheight, config. argb_8888); colormatrix cmatrix = new colormatrix (); // sets the saturation cmatrix. setsaturation (float) (Progress/100.0); P Aint paint = new paint (); paint. setcolorfilter (New colormatrixcolorfilter (cmatrix); canvas = new canvas (BMP); // draw an existing bitmap on the canvas. In this way, dstbitmap is the same as srcbitmap in canvas. drawbitmap (srcbitmap, 0, 0, paint); dstimage. setimagebitmap (BMP);} public void onstarttrackingtouch (seekbar bar) {}} public void onstoptrackingtouch (seekbar bar) {}}); brightnessseekbar. setonseekbarchangelistener (New onseekbarchangelistener () {// This method is triggered when the slider position of the drag bar changes public void onprogresschanged (seekbar arg0, int progress, Boolean fromuser) {bitmap BMP = bitmap. createbit Map (imgwidth, imgheight, config. argb_8888); int brightness = progress-127; colormatrix cmatrix = new colormatrix (); cmatrix. set (new float [] {1, 0, 0, 0, brightness, 0, 1, 0, 0, brightness, // change the brightness of 0, 0, 1, 0, brightness, 0, 0, 0, 1, 0}); paint = new paint (); paint. setcolorfilter (New colormatrixcolorfilter (cmatrix); canvas = new canvas (BMP); // draw an existing bitmap on the canvas. In this way, dstbitmap is the same as srcbitmap in canvas. drawbitmap (srcbitmap, 0, 0, paint); dstimage. setimagebitmap (BMP);} public void onstarttrackingtouch (seekbar bar) {}} public void onstoptrackingtouch (seekbar bar) {}}); contrastseekbar. setonseekbarchangelistener (New onseekbarchangelistener () {// This method is triggered when the slider position of the drag bar changes public void onprogresschanged (seekbar arg0, int progress, Boolean fromuser) {bitmap BMP = bitmap. createbitma P (imgwidth, imgheight, config. argb_8888); // int brightness = progress-127; float contrast = (float) (Progress + 64)/128.0); colormatrix cmatrix = new colormatrix (); cmatrix. set (new float [] {contrast, 0, 0, 0, 0, 0, 0, contrast, 0, 0, // change the contrast of 0, 0, contrast, 0, 0, 0, 0, 0, 1, 0}); paint = new paint (); paint. setcolorfilter (New colormatrixcolorfilter (cmatrix); canvas = new canvas (BMP );// Draw an existing bitmap on the canvas. In this way, dstbitmap is the same as srcbitmap in canvas. drawbitmap (srcbitmap, 0, 0, paint); dstimage. setimagebitmap (BMP);} public void onstarttrackingtouch (seekbar arg0) {// todo auto-generated method stub} public void onstoptrackingtouch (seekbar) {// todo auto-generated method stub});}/*** the image to be loaded may be a large image, we need to perform proper reduction processing for it ** @ Param imageuri */private bitmap getsrcimage (URI imageuri) {try {bitmapfactory. options Ops = new bitmapfactory. options (); ops. injustdecodebounds = true; bitmap BMP = bitmapfactory. decodestream (this. getcontentresolver (). openinputstream (imageuri), null, OPS); int wratio = (INT) math. ceil (Ops. outwidth/(float) max_width); int hratio = (INT) math. ceil (Ops. outheight/(float) max_height); If (wratio> 1 & hratio> 1) {If (wratio> hratio) {ops. insamplesize = wratio;} else {ops. insamplesize = hratio ;}} ops. injustdecodebounds = false; BMP = bitmapfactory. decodestream (this. getcontentresolver (). openinputstream (imageuri), null, OPS); Return BMP;} catch (filenotfoundexception e) {// todo auto-generated catch blocke. printstacktrace (); log. E (this. getclass (). getname (), E. getmessage () ;}return null ;}}

Layout file, relatively simple:

<? XML version = "1.0" encoding = "UTF-8"?> <Linearlayout xmlns: Android = "http://schemas.android.com/apk/res/android" Android: layout_width = "fill_parent" Android: layout_height = "fill_parent" Android: Orientation = "vertical"> <imageview Android: id = "@ + ID/dstimageview" Android: scaletype = "fitcenter" Android: layout_width = "fill_parent" Android: layout_height = "wrap_content" Android: maxwidth = "240px" Android: maxheight = "240px"/> <linearlayout Android: layout_widt H = "fill_parent" Android: layout_height = "wrap_content" Android: Orientation = "vertical"> <linearlayout Android: layout_width = "fill_parent" Android: layout_height = "wrap_content" Android: orientation = "horizontal" Android: Orientation = "true" Android: gravity = "center_vertical"> <textview Android: layout_width = "wrap_content" Android: layout_height = "wrap_content" Android: TEXT = "@ string/saturation"/> <! -- Define a drag bar and change its slider appearance --> <seekbar Android: Id = "@ + ID/saturationseekbar" Android: layout_width = "fill_parent" Android: layout_height = "wrap_content" Android: Progress = "100" Android: max = "200"/> </linearlayout> <linearlayout Android: layout_width = "fill_parent" Android: layout_height = "wrap_content" Android: Orientation = "horizontal" Android: gravity = "center_vertical"> <textview Android: layout_width = "wrap_content" Android: Layout_height = "wrap_content" Android: text = "@ string/brightness"/> <! -- Define a drag bar and change its slider appearance --> <seekbar Android: Id = "@ + ID/brightnessseekbar" Android: layout_width = "fill_parent" Android: layout_height = "wrap_content" Android: Progress = "127" Android: max = "255"/> </linearlayout> <linearlayout Android: layout_width = "fill_parent" Android: layout_height = "wrap_content" Android: Orientation = "horizontal" Android: gravity = "center_vertical"> <textview Android: layout_width = "wrap_content" Android: Layout_height = "wrap_content" Android: text = "@ string/contrast"/> <! -- Define a drag bar and change its slider appearance --> <seekbar Android: Id = "@ + ID/contrastseekbar" Android: layout_width = "fill_parent" Android: layout_height = "wrap_content" Android: Progress = "63" Android: max = "127"/> </linearlayout>

Running result: