如何以编程方式更改图像中的颜色？

Question

我有一个带有透明背景的 .PNG 图像和一个黑色的绘图，我怎么能以编程方式将此图像中的“黑色绘图颜色”更改为我想要的任何颜色；使用 rim 4.5 API？ 提前致谢....

Answer 1

我找到了解决方案，这里是给有兴趣的人的。

Bitmap colorImage(Bitmap image, int color) {
    int[] rgbData= new int[image.getWidth() * image.getHeight()];
    image.getARGB(rgbData, 
                  0, 
                  image.getWidth(), 
                  0, 
                  0, 
                  image.getWidth(), 
                  image.getHeight());
    for (int i = 0; i < rgbData.length; i++) {
        int alpha = 0xFF000000 & rgbData[i];
        if((rgbData[i] & 0x00FFFFFF) == 0x00000000)
            rgbData[i]= alpha | color;
    }
    image.setARGB(rgbData,
                  0, 
                  image.getWidth(),
                  0,
                  0,
                  image.getWidth(),
                  image.getHeight());
    return image;
}

Answer 2

您可以解析图像 RGB，搜索黑色并将其替换为您想要的任何颜色。

Answer 3

您可以将 PNG 图像读取到字节数组并编辑调色板块。 此方法仅适用于 PNG-8 图像。 这是我的代码：

public static Image createImage(String filename) throws Throwable { DataInputStream dis = null; InputStream is = null; try { is = new Object().getClass().getResourceAsStream(filename); dis = new DataInputStream(is); int pngLength = dis.available(); byte[] png = new byte[pngLength]; int offset = 0; dis.read(png, offset, 4); offset += 4; //‰PNG dis.read(png, offset, 4); offset += 4; //.... while (true) { //length dis.read(png, offset, 4); offset += 4; int length = (png[offset-1]&0xFF) | ((png[offset-2]&0xFF)<<8) | ((png[offset-3]&0xFF)<<16) | ((png[offset-4]&0xFF)<<24); //chunk type dis.read(png, offset, 4); offset += 4; int type = (png[offset-1]&0xFF) | ((png[offset-2]&0xFF)<<8) | ((png[offset-3]&0xFF)<<16) | ((png[offset-4]&0xFF)<<24); //chunk data for (int i=0; i<length; i++) { dis.read(png, offset, 1); offset += 1; } //CRC dis.read(png, offset, 4); offset += 4; int crc = (png[offset-1]&0xFF) | ((png[offset-2]&0xFF)<<8) | ((png[offset-3]&0xFF)<<16) | ((png[offset-4]&0xFF)<<24); if (type == 0x504C5445) { //'PLTE' int CRCStart = offset-4; int PLTEStart = offset-4-length; //modify PLTE chunk for (int i=PLTEStart; i<PLTEStart+length; i+=3) { png[i+0] = ... png[i+1] = ... png[i+2] = ... } int newCRC = crc(png, PLTEStart-4, length+4); png[CRCStart+0] = (byte)(newCRC>>24); png[CRCStart+1] = (byte)(newCRC>>16); png[CRCStart+2] = (byte)(newCRC>>8); png[CRCStart+3] = (byte)(newCRC); } if (offset >= pngLength) break; } return Image.createImage(png, 0, pngLength); } catch (Throwable e) { throw e; } finally { MainCanvas.closeInputStream(dis); MainCanvas.closeInputStream(is); } }