[英]Rotate 90 degree to right image in java
我無法將圖像向右旋轉90度。 我需要能夠在java中單獨旋轉圖像。 唯一的事情。 不幸的是,我需要在特定的點繪制圖像,並且沒有一個方法可以分別對圖像進行旋轉,並且2.允許我設置x和y。 任何幫助表示贊賞
public class Tumbler extends GraphicsProgram{
public void run() {
setSize(1000,1000);
GImage original = new GImage("sunset.jpg");
add(original, 10, 10);
int[][] pixels = original.getPixelArray();
int height = pixels.length;
int width = pixels[0].length;
// Your code starts here
int newheight = width;
int newwidth = height;
int[][] newpixels = new int[newheight][newwidth];
for (int i = 0; i < height; i++) {
for (int j = 0; j < width; j++) {
newpixels[j][height-1-i] = pixels[i][j];
}
}
GImage image = new GImage(newpixels);
add(image, width+20, 10);
// Your code ends here
}
如果我們想要具有不錯的性能(與直接復制像素相比快~10倍),我們絕對應該使用Graphics2D:
public static BufferedImage rotateClockwise90(BufferedImage src) {
int width = src.getWidth();
int height = src.getHeight();
BufferedImage dest = new BufferedImage(height, width, src.getType());
Graphics2D graphics2D = dest.createGraphics();
graphics2D.translate((height - width) / 2, (height - width) / 2);
graphics2D.rotate(Math.PI / 2, height / 2, width / 2);
graphics2D.drawRenderedImage(src, null);
return dest;
}
這是我用來順時針旋轉BufferedImage 90度的代碼。 由於旋轉90度是一種特殊情況,我認為任何角度的通用解決方案都不具備最佳性能。 同樣,對於執行某種插值(雙線性,雙三次等)的解決方案,我使用BufferedImage.getRaster()來訪問原始字節以提高性能,但是根據圖像的結構/布局,這不太可能在所有情況下工作。 因人而異。
public static BufferedImage rotateClockwise90(BufferedImage src) {
int srcWidth = src.getWidth();
int srcHeight = src.getHeight();
boolean hasAlphaChannel = src.getAlphaRaster() != null;
int pixelLength = hasAlphaChannel ? 4 : 3;
byte[] srcPixels = ((DataBufferByte)src.getRaster().getDataBuffer()).getData();
// Create the destination buffered image
BufferedImage dest = new BufferedImage(srcHeight, srcWidth, src.getType());
byte[] destPixels = ((DataBufferByte)dest.getRaster().getDataBuffer()).getData();
int destWidth = dest.getWidth();
int srcPos = 0; // We can just increment this since the data pack order matches our loop traversal: left to right, top to bottom. (Just like reading a book.)
for(int srcY = 0; srcY < srcHeight; srcY++) {
for(int srcX = 0; srcX < srcWidth; srcX++) {
int destX = ((srcHeight - 1) - srcY);
int destY = srcX;
int destPos = (((destY * destWidth) + destX) * pixelLength);
if(hasAlphaChannel) {
destPixels[destPos++] = srcPixels[srcPos++]; // alpha
}
destPixels[destPos++] = srcPixels[srcPos++]; // blue
destPixels[destPos++] = srcPixels[srcPos++]; // green
destPixels[destPos++] = srcPixels[srcPos++]; // red
}
}
return dest;
}
Ken答案的簡化版本:
public static BufferedImage rotateClockwise90(BufferedImage src) {
int w = src.getWidth();
int h = src.getHeight();
BufferedImage dest = new BufferedImage(h, w, src.getType());
for (int y = 0; y < h; y++)
for (int x = 0; x < w; x++)
dest.setRGB(y, w - x - 1, src.getRGB(x, y));
return dest;
}
作為討論在這里 ,你可以使用AffineTransformOp
旋轉由圖像Math.PI / 2
; 這相當於對圖像進行順時針旋轉90°,如圖所示在這里 。 另請參閱處理90度旋轉 。
將圖像旋轉到90度,180度或270度角
public static BufferedImage rotateImage(BufferedImage src, int rotationAngle) {
double theta = (Math.PI * 2) / 360 * rotationAngle;
int width = src.getWidth();
int height = src.getHeight();
BufferedImage dest;
if (rotationAngle == 90 || rotationAngle == 270) {
dest = new BufferedImage(src.getHeight(), src.getWidth(), src.getType());
} else {
dest = new BufferedImage(src.getWidth(), src.getHeight(), src.getType());
}
Graphics2D graphics2D = dest.createGraphics();
if (rotationAngle == 90) {
graphics2D.translate((height - width) / 2, (height - width) / 2);
graphics2D.rotate(theta, height / 2, width / 2);
} else if (rotationAngle == 270) {
graphics2D.translate((width - height) / 2, (width - height) / 2);
graphics2D.rotate(theta, height / 2, width / 2);
} else {
graphics2D.translate(0, 0);
graphics2D.rotate(theta, width / 2, height / 2);
}
graphics2D.drawRenderedImage(src, null);
return dest;
}
這是使用2D數組的代碼:
`private static int[][] rorateImage
(int[][] imageArr, int rows, int columns, int flag){
int rotatedImageArr[][] = new int[columns][rows];
if(flag==1){ //90 degree rotation in right
for (int i = 0; i < columns; i++) {
for (int j = 0; j < rows; j++) {
rotatedImageArr[i][j] = imageArr[rows - 1 - j][i];
}
}
}
if(flag==0){ //90 degree rotation in left
for (int i = 0; i < columns; i++) {
for (int j = 0; j < rows; j++) {
rotatedImageArr[i][j] = imageArr[j][columns -1 -i];
}
}
}
return rotatedImageArr;
}`
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.