Detect pixel color from Raster

Hi
I am trying to count the number of white pixels I have in a grayscale TIFF image, using JAI I get a buffered image then pass in a portion of the image (raster) to a method. This works fine for some of my images and not at all with others, I have, after lots of pain and suffering ive found out that in some of the images a white pixel is 0 while in others it is -1.
I am counting white pixels and considering all others black ...to allow bi-tonal and grayscale images alike. I am lost as far as these images are concerned ...my guess is that the info i need is in the sample model but i have spent more time researching the inner workings of image than the scope of my project requires already
so im hoping someone can help me out here ...all i wanna do is detect a white pixel in a raster (hopefully this is as easy as it sounds)
-Jerome BG

Well after doin a bunch of reading and investigative work I know way more about image rendering and visualization than I ever wanted to know. So I know that you cant determine the pixel's color without the ColorModel, but since I can convert grayscale images to bi-tonal i know all ill have is 0 or 1 ...I still dunno how to use the ColorModel to determine which is which, but its not so important since all my images have white as 0.
Any ways if anyone out there is as obtuse as my self just using:
myRaster.getSample(x,y,band)(only one band for bi-tonal images) you get the bit as an int.
If anyone knows how to determine how to find out rather white or black is 0 using the Raster and the ColorModel I would still like to know
-Jeorme BG

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Reading pixel color from Image?

Hello frnds,
I am making a project in which i have to upload Image, am trying to find color of each pixel in RGB format so that I can locate where my sprite begins in Image !!
But I am not able to do so.. do I have to use PixelGrabber to do that? or should i use RGBImageFilter..!! I am new to java so if u can tell me how to use them, then It would be grateful.
I want to scan whole image from left to right, Right to left, top to bottom and vice-versa. So that I can exactly tell at what pixel value sprite starts and ends.
Please help me out. any sort of help will be useful for my project..
Thanking you in advance.

Image bufferImage;PixelGrabber pg1;
public boolean fetchPixels(byte[] jpegData, int[] pixelData)
     try
          bufferImage = Toolkit.getDefaultToolkit().createImage(jpegData);
          // this may not be required unless asynchronous, but seems to do no harm
          MediaTracker mt = new MediaTracker(jcamData);
          mt.addImage(bufferImage, 0);
          try
               mt.waitForID(0);
          catch(InterruptedException e)
               e.printStackTrace();
          if(mt.isErrorAny()==true)
               System.out.println("Exception fetchPixels "+"createImage failed");
               // flush anything in bufferedImage
               if(bufferImage!=null)bufferImage.flush();
               return false;     // and pixelData not updated
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          pg1 = new PixelGrabber(bufferImage, 0, 0, camWidth, camHeight, pixelData, 0, camWidth);
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          Thread.yield();
          // flush bufferedImage as no longer needed, and so not to be in memory cache for next image load
          if(bufferImage!=null)
               bufferImage.flush();
     catch(Exception e){System.out.println("Exception fetchPixels "+e);}
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}

Please Help Get a Color from Pixel !!!!

Is anybody know how to get a Color from pixel.
My program is not Full Screen .
So i think Robot.getPixelColor() don't suitable.
Please Help me!

Robot.getPixelColor() will work fine, but the problem you will have is getting the mouse set to the correct location and getting your application to know where it is: you can do it with win32 calls and JNI. Here are a few that I have found helpful--they are in a VB format:
Public Const CLR_INVALID = &HFFFF 'not a valid pixel
Public Const MOUSE_MOVED = &H1
Public Const MOUSEEVENTF_ABSOLUTE = &H8000 ' absolute move
Public Const MOUSEEVENTF_LEFTDOWN = &H2 ' left button down
Public Const MOUSEEVENTF_LEFTUP = &H4 ' left button up
Public Const MOUSEEVENTF_RIGHTDOWN = &H8 ' right button down
Public Const MOUSEEVENTF_RIGHTUP = &H10 ' right button up
Public Const REQUEST_LEFT_CLICK = &H2D 'request left click "-"
Public Const REQUEST_RIGHT_CLICK = &H2B 'request right click "+"
Type POINTAPI
x As Long
y As Long
End Type
Type POINTSTRUCT
hwnd As Long
hdc As Long
ptAbsolute As POINTAPI
ptOrigin As POINTAPI
ptLocal As POINTAPI
ptColor As Long
sType As String
retMessage As Boolean
End Type
Declare Function GetCursorPos _
Lib "user32" (ByRef lpPoint As POINTAPI) _
As Long
Declare Function SetCursorPos _
Lib "user32" (ByVal x As Long, ByVal y As Long) _
As Long
Declare Sub mouse_event _
Lib "user32" (ByVal dwFlags As Long, _
ByVal dx As Long, _
ByVal dy As Long, _
ByVal cButtons As Long, _
ByVal dwExtraInfo As Long)
Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
Declare Function GetMessageExtraInfo Lib "user32" () As Long
Declare Function GetPixel Lib "gdi32" (ByVal hdc As Long, _
ByVal x As Long, _
ByVal y As Long) As Long
Declare Function WindowFromPoint Lib "user32" (ByVal xPoint As Long, _
ByVal yPoint As Long) As Long
Declare Function GetWindowDC Lib "user32" (ByVal hwnd As Long) As Long
Declare Function GetWindowOrgEx Lib "gdi32" (ByVal hdc As Long, _
ByRef lpPoint As POINTAPI) As Long

Photoshop CS2: Get CMYK color from pixel?

Hi, in Photoshop CS3 I can use colorSamplers to pick up a CMYK color from a pixel. But I haven't found anything in the CS2 scripting reference about that.
I cannot use channels["cyan"].histogram, because I need the calculated %-value (0100) from Photoshop, not the color index number (0255).
Example:
A pixel was filled with 70% cyan, Photoshop uses internally 69,8% and that's the value I want to read through a script.
Any suggestions? :-)

[email protected] wrote:
> Hi, in Photoshop CS3 I can use colorSamplers to pick up a CMYK color from a pixel. But I haven't found anything in the CS2 scripting reference about that.
>
> I cannot use channels["cyan"].histogram, because I need the calculated %-value (0100) from Photoshop, not the color index number (0255).
>
> Example:
> A pixel was filled with 70% cyan, Photoshop uses internally 69,8% and that's the value I want to read through a script.
>
> Any suggestions? :-)
Try this:
var cyanPercent = (channels["cyan"].histogram/255) * 100;
-X
for photoshop scripting solutions of all sorts
contact: [email protected]

Convert colour images to grayscale images & get pixel data from them

Is the code below correct to convert colour images to grayscale images in Java?
public void convertToGrayscale (String sourceName,String destName) throws Exception {
JPEGImageDecoder decoder=JPEGCodec.createJPEGDecoder(new FileInputStream(sourceName));
JPEGImageEncoder encoder=JPEGCodec.createJPEGEncoder(new FileOutputStream(destName));
BufferedImage sourceImg=decoder.decodeAsBufferedImage();
BufferedImageOp op =new ColorConvertOp(
ColorSpace.getInstance(ColorSpace.CS_GRAY),null);
BufferedImage destImg = op.filter(sourceImg,null);
encoder.encode(destImg);
decoder = null;
encoder = null;
When I get grayscale images from the code below, I would like to access the pixels of those images. So I tried to do:
byte[] dd=((DataBufferByte)mImage.getRaster().getDataBuffer()).getData();
BUT the data result array is not 0-255. Could anyone suggest how to obtain pixel data from grayscale images?
In case that my code shown is not correct or suitable, please give your advice. What I would like to do are in the steps as follows:
1 change 100*70 jpeg-images to 100*70 grayscale images.
2 create two dimensional array of pixel data (example [100][70]) from converted images. The number in the array should be between 0-255, right??? And 0 refers to black colour and 255 refers to white colour???
I am confused about grayscale images. Please help.
Thank you so much

I am not sure i understand what is the problem exactly.
Structure of DataBuffer is described by SampleModel used by same Raster
object. E.g. it might be 1 byte per xipex or 4 bytes per pixel.
In your example convertToGrayscale saves images to file as JPEG and
it seems you later read it back. It is possible what image you read back
is not greyscale but ARGB and data buffer has different format.
Technically, if you just need level of grey you may simply
call getRGB on your output image. Grey is uniform mix of R, G and B.
Also, instead of ColorConverOp you may dimply create output image of
grayscale type and draw your color input image with drawImage().
If none of these helps please try to provide more details.

Magic Wand Selection Tool Fails to Operate on Precise Pixel Color

I had an interesting thing happen with Photoshop CS5... My Magic Wand tool got to where it wasn't selecting pixel colors based on the one under the tip of the tool when clicked. It was selecting what seemed like similar colors, but its operation wasn't really predictable.
It turns out that in a prior unrelated operation (days ago) I had changed the color picker to look at a very large number of pixels when sampling.
Having chosen the above, the setting was sticky and modal (meaning it subsequently affected samples taken from then on by a variety of tools).
I didn't think that this should affect subsequent samples taken with the Magic Wand tool. I'm not sure this has always been the case, but it doesn't seem as though it should work this way.
Notably I don't see any way, while the Magic Wand tool is active, that the above sample size can be changed. Nor did Resetting the Magic Wand tool correct the situation.
Should the previously selected color picker sample size actually affect the Magic Wand tool, or is this a case where someone at Adobe consolidated the pixel sampling logic a bit too aggressively?
If the latter, here's an adage to post in the halls of Adobe Engineering: "Make everything as simple as possible, but no simpler."
-Noel

Hm, appears to be an old issue: http://forums.adobe.com/message/3226358
What I can't fathom is that it's never bitten me before. I do tend to leave the eyedropper on 1 x 1 pixels, but I occasionally do sample larger regions.
-Noel

How to get max 5 color from image??

I try to get max 5 color from image (ex. jpeg,gif) ,I use PixelGrabber
it too slowly when i use large image,Please help me, to run more fast
(other way PixelGrabber)
best regard
[email protected],[email protected]
source below:
public String generateColor(InputStream source,String filePath){
BufferedImage image = null;
String RGB = "";
System.out.println("==generateColor==");
try {
image = ImageIO.read(source);
catch (IOException ex1) {
ex1.printStackTrace();
//image.getGraphics().getColor().get
// BufferedImage image2 = ImageIO.read(source);
// image.getColorModel().getNumColorComponents()
if(image.getColorModel() instanceof IndexColorModel) {
IndexColorModel icm = (IndexColorModel)image.getColorModel();
byte[][] data = new byte[3][icm.getMapSize()];
int[] rgbB = new int[icm.getMapSize()];
icm.getRGBs(rgbB);
String dataHtm = "<HTML><table width=\"100\" border=\"0\"><tr>";
for(int i = 0 ;i< rgbB.length;i++){
int r = (rgbB[i] >> 16) & 0xff;
int g = (rgbB[i] >> 8) & 0xff;
int k = (rgbB) & 0xff;
System.out.println("red:" + Integer.toHexString(r));
System.out.println("green:" + Integer.toHexString(g));
System.out.println("blue:" + Integer.toHexString(k));
dataHtm = dataHtm + "<td width=\"10\" bgcolor=\"#" + Integer.toHexString(r)+Integer.toHexString(g)+Integer.toHexString(k);
dataHtm = dataHtm + "\"> </td>";
dataHtm = dataHtm + "</tr></table></HTML>";
try {
BufferedWriter out = new BufferedWriter(new FileWriter("c:\\23289207.html"));
out.write(dataHtm);
out.close();
catch (IOException e) {
e.printStackTrace();
int w = image.getWidth();
int h = image.getHeight();
int[] pixels = new int[w*h];
int[] pixs = new int[w*h];
System.out.println("image width:"+w+"image hight:"+h+"image w*h:"+(w*h));
Image img = Toolkit.getDefaultToolkit().getImage(filePath);
PixelGrabber pg = new PixelGrabber(img, 0,0, w, h, pixels, 0, w);
try {
pg.grabPixels();
catch (Exception x) {
x.printStackTrace();
String picColor = "";
Stack stackColor = new Stack();
Hashtable hashColor = new Hashtable();
for (int i = 0; i < w * h; i++) {
int rgb = pixels[i];
int a = (rgb >> 24) & 0xff;
int r = (rgb >> 16) & 0xff;
int g = (rgb >> 8) & 0xff;
int k = (rgb) & 0xff;
i = i+1000;
//System.out.println("i:" + i);
picColor = convertToSring(r)+convertToSring(g)+convertToSring(k);
stackColor.add(picColor);
//System.out.println("picColor:"+picColor);
// System.out.println("\n\n a:" + a);
// System.out.println("red:" + r);
// System.out.println("green:" + g);
// System.out.println("blue:" + k);
}//end for
getMaxColor(stackColor);
System.out.println("==generateColor==end\n\n");
return null;

import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
public class HighFive
    private void examineColors(BufferedImage image)
        long start = System.currentTimeMillis();
        int w = image.getWidth(), h = image.getHeight();
        int[] rgbs = image.getRGB(0,0,w,h,null,0,w);
        findHighFive(rgbs);
        long end = System.currentTimeMillis();
        System.out.println("total time = " + (end - start)/1000.0 + " seconds");
    private void findHighFive(int[] colors)
        int[] uniqueColors = getUniqueColors(colors);
        int[] colorCounts = getColorCounts(uniqueColors, colors);
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        // and use this index to find color code in uniqueColors
        for(int j = 0; j < highFive.length; j++)
            int index = findIndexInArray(colorCounts, highFive[j]);
            Color color = new Color(uniqueColors[index]);
            String s = color.toString();
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            System.out.println("color " + s + " occurs " +
                                highFive[j] + " times");
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        int[] uniqueColors = new int[colors.length];
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                uniqueColors[count++] = colors[j];
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            int index = findIndexInArray(uniqueColors, colors[j]);
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        // find five highest values in colorCounts
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        int count = 0;
        for(int j = 0; j < highFive.length; j++)
            int max = Integer.MIN_VALUE;
            for(int k = 0; k < colorCounts.length; k++)
                if(colorCounts[k] > max)
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                        max = colorCounts[k];
                        highFive[count] = colorCounts[k];
            count++;
        return highFive;
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        for(int j = 0; j < n.length; j++)
            if(n[j] == target)
                return false;
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        for(int j = 0; j < n.length; j++)
            if(n[j] == target)
                return j;
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        String path = "images/cougar.jpg";
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        BufferedImage image = ImageIO.read(((URL)o).openStream());
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}

Skin colors from variables?

My app is shaping up to use several skins. Not a problem, but I'd like to have a way to reference a global variable for a color used in a skin.
For example, if I have something like
     
     <s:Rect left="1" right="1" top="1" height="30">
        <s:fill>
        <s:LinearGradient rotation="90">
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        <s:GradientEntry color="0xD3B36D" alpha="1"/>
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        </s:fill>
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I would like to set, in the main app, a pair of variables such as
[Bindable] public var gradStart:String = "0xE8D8B4"
and then use in the component for the gradient entry.
Is this possible? What's the syntax?

I've never used getters and setters. I will need to look into it. Thanks.
I tried using
[Bindable]
public var testColor:String = "0xff0000";
in the main app and then:
color="{FlexGlobals.topLevelApplication.testColor}" in the component. It did work, surprisingly, except for a warning about not being able to detect changes to testColor.
What I ulitmately need to do is to be able to have all these values in an XML file, load that into an XMLListCollection and then "assign" the colors from that. What would be ideal is if I could do it right from the list, something like:
[Bindable]
public var styleList:XMLListCollection; // contains the xml data
then
color="{styleList.window[0].colorValue}"
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Get color from image

Hey people, I'm new to Illustrator and have a question. I want to use a color from an image that I put into Illustrator.
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Any help would be greatly appreciated!
PS apologies for any unavoidable noobness

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Always state what software version you are using.
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There is no Image object there is only a paintPanel object.
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ChangChiTheGraphics
chang Chi

Hello C.H.Chi
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place a image in your resource file and access from their.
Kindly mark as answer if found useful.

How can I change the background of a running webpage on my own. Example Facebook I want to change its backround color from white to black just in my view not for all

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Why am I unable to change text color from black in LR5 book module?

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Detect pixel color from Raster

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