/**
* Copyright (c) 2012-2013 Nokia Corporation. All rights reserved.
* Nokia and Nokia Connecting People are registered trademarks of Nokia Corporation.
* Oracle and Java are trademarks or registered trademarks of Oracle and/or its
* affiliates. Other product and company names mentioned herein may be trademarks
* or trade names of their respective owners.
* See LICENSE.TXT for license information.
*/
package com.nokia.example.picasaviewer.util;
import com.nokia.mid.ui.DirectUtils;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Image;
/**
* Utilities for handling images.
*/
public class ImageUtils {
/**
* Sets the alpha of the each pixel in the image based on the given value.
* @param image The original image.
* @param alpha The alpha value.
* @return A newly created image with applied alpha.
* @throws NullPointerException If the given image is null.
* @throws IllegalArgumentException If the alpha value is not in [0, 255].
*/
public static Image setAlpha(final Image image, final int alpha)
throws NullPointerException, IllegalArgumentException
{
if (image == null) {
throw new NullPointerException();
}
if (alpha < 0 || alpha > 255) {
throw new IllegalArgumentException();
}
final int width = image.getWidth();
final int height = image.getHeight();
final int[] originalRgb = new int[width * height];
image.getRGB(originalRgb, 0, width, 0, 0, width, height);
final int opaqueRgb[] = new int[width * height];
for (int x = 0; x < width; ++x) {
for (int y = 0; y < height; ++y) {
if (originalRgb[(width * y) + x] >>> 24 == 255) {
opaqueRgb[(width * y) + x] =
originalRgb[(width * y) + x] + (alpha << 24);
}
else {
opaqueRgb[(width * y) + x] = originalRgb[(width * y) + x];
}
}
}
return Image.createRGBImage(opaqueRgb, width, height, true);
}
/**
* Subtracts the given RGB values from the given image while maintaining
* the alpha level of each pixel.
* @param image The original image.
* @param r Red value to subtract.
* @param g Green value to subtract.
* @param b Blue value to subtract.
* @return The modified image.
* @throws NullPointerException If the given image is null.
* @throws IllegalArgumentException If any of RGB values is invalid.
*/
public static Image substractRgb(final Image image,
final int r,
final int g,
final int b)
throws NullPointerException, IllegalArgumentException
{
if (image == null) {
throw new NullPointerException();
}
if (r < 0 || r > 255 || g < 0 || g > 255 || b < 0 || b > 255) {
throw new IllegalArgumentException();
}
final int[] rgbToSubstract = new int[3];
rgbToSubstract[0] = r;
rgbToSubstract[1] = g;
rgbToSubstract[2] = b;
final int width = image.getWidth();
final int height = image.getHeight();
final int[] originalRgb = new int[width * height];
image.getRGB(originalRgb, 0, width, 0, 0, width, height);
final int newRgb[] = new int[width * height];
int pixel = 0;
int[] argb = new int[4];
for (int x = 0; x < width; ++x) {
for (int y = 0; y < height; ++y) {
pixel = originalRgb[(width * y) + x];
argb[0] = (pixel & 0xff000000) >>> 24;
argb[1] = (pixel & 0x00ff0000) >>> 16;
argb[2] = (pixel & 0x0000ff00) >>> 8;
argb[3] = pixel & 0x000000ff;
for (int i = 0; i < 3; ++i) {
if (argb[i + 1] - rgbToSubstract[i] >= 0) {
argb[i + 1] -= rgbToSubstract[i];
}
else {
argb[i + 1] = 0;
}
}
newRgb[(width * y) + x] =
(argb[0] << 24) | (argb[1] << 16) | (argb[2] << 8) | argb[3];
}
}
return Image.createRGBImage(newRgb, width, height, true);
}
/**
* Scales the given image.
* @param image The original image.
* @param newWidth The new image width.
* @param newHeight The new image height.
* @return The scaled image.
*/
public static Image scale(final Image image,
final int newWidth,
final int newHeight)
{
if (newWidth <= 0 || newHeight <= 0 || image == null) {
throw new IllegalArgumentException(
"Invalid width or height or the given image is null!");
}
// Get the size and the RGB array of the original image
final int sourceWidth = image.getWidth();
final int sourceHeight = image.getHeight();
final int[] originalRgb = new int[sourceWidth * sourceHeight];
image.getRGB(originalRgb, 0, sourceWidth, 0, 0, sourceWidth, sourceHeight);
final int scaledRgb[] = new int[newWidth * newHeight];
for (int y = 0; y < newHeight; y++) {
final int dy = y * sourceHeight / newHeight;
for (int x = 0; x < newWidth; x++) {
final int dx = x * sourceWidth / newWidth;
scaledRgb[(newWidth * y) + x] = originalRgb[(sourceWidth * dy) + dx];
}
}
return Image.createRGBImage(scaledRgb, newWidth, newHeight, true);
}
/**
* This method takes an image and overlays all the visible pixels with the
* specified color. This is useful for single color icons that should be
* colored according to the theme of the device.
*
* @param image The original image.
* @return The resulting image.
*/
public static Image drawMaskedImage(Image image, Display display) {
final int color = display.getColor(Display.COLOR_HIGHLIGHTED_BORDER);
// Store the pixel array of the image
final int[] sourceData = new int[image.getHeight() * image.getWidth()];
image.getRGB(
sourceData,
0,
image.getWidth(),
0,
0,
image.getWidth(),
image.getHeight());
// Overlay non-transparent pixels with the specified color
for (int i = 0; i < sourceData.length; i++) {
sourceData[i] =
(sourceData[i] & 0xFF000000) | (color & 0x00FFFFFF);
}
// Create the new image
final Image overlayed =
DirectUtils.createImage(
image.getWidth(),
image.getHeight(),
0x000000);
overlayed.getGraphics().drawRGB(
sourceData,
0,
image.getWidth(),
0,
0,
image.getWidth(),
image.getHeight(),
true);
return overlayed;
}
}