PHP? ???? ??? ??? ??? ???? ??

??? ??? ??? ??? ??? ???? ? ??? ?? ? ?????. ??? ????? ??? ???? ??? ? ?? ?? ? ??? ?? ? ???, ??? ???? ??? ??? ?? ?? ??? ????? ???? ? ????.

PHP? ????? ???? ?? ? ???? ??? ??? ??? ?? ??? ?????? ?????. ? ????? PHP? ???? ???? ??? ??? ???? ??? ?? ??? ?? ?????.

1. ?? ?? ??

??? RGB ?? ???? ??? ??? ??? ? ????. ??? PHP GD ?????? ???? ???? ??? ???? ?? ?????.

function adjustBrightness($imagePath, $brightness) {
    $image = imagecreatefromjpeg($imagePath);
    $width = imagesx($image);
    $height = imagesy($image);

    for ($x = 0; $x < $width; $x++) {
        for ($y = 0; $y < $height; $y++) {
            $rgb = imagecolorat($image, $x, $y);
            $oldR = ($rgb >> 16) & 0xFF;
            $oldG = ($rgb >> 8) & 0xFF;
            $oldB = $rgb & 0xFF;

            $newR = $oldR + $brightness;
            $newG = $oldG + $brightness;
            $newB = $oldB + $brightness;

            $newR = max(0, min(255, $newR));
            $newG = max(0, min(255, $newG));
            $newB = max(0, min(255, $newB));

            $newRgb = ($newR << 16) + ($newG << 8) + $newB;

            imagesetpixel($image, $x, $y, $newRgb);
        }
    }

    imagejpeg($image, 'adjusted_image.jpg');
    imagedestroy($image);
}

// 使用示例
adjustBrightness('original_image.jpg', 50); // 將亮度增加50

? ??? ???? ? ??? ???? ?? RGB ?? ?? ??? ?? ?? ???? ? RGB ?? ??? ?? imagesetpixel ??? ???? ? ?? ?? ?????. ????? ??? ??? ?????. imagesetpixel函數(shù)設(shè)置新的像素值，最終生成一張調(diào)整后的圖片。

2. 調(diào)整圖片對比度

調(diào)整圖片的對比度可以通過調(diào)整像素的RGB值的范圍來實(shí)現(xiàn)。下面是一個示例函數(shù)，使用PHP GD庫來調(diào)整圖片的對比度。

function adjustContrast($imagePath, $contrast) {
    $image = imagecreatefromjpeg($imagePath);
    $width = imagesx($image);
    $height = imagesy($image);

    for ($x = 0; $x < $width; $x++) {
        for ($y = 0; $y < $height; $y++) {
            $rgb = imagecolorat($image, $x, $y);
            $oldR = ($rgb >> 16) & 0xFF;
            $oldG = ($rgb >> 8) & 0xFF;
            $oldB = $rgb & 0xFF;

            $newR = ($oldR - 127) * $contrast + 127;
            $newG = ($oldG - 127) * $contrast + 127;
            $newB = ($oldB - 127) * $contrast + 127;

            $newR = max(0, min(255, $newR));
            $newG = max(0, min(255, $newG));
            $newB = max(0, min(255, $newB));

            $newRgb = ($newR << 16) + ($newG << 8) + $newB;

            imagesetpixel($image, $x, $y, $newRgb);
        }
    }

    imagejpeg($image, 'adjusted_image.jpg');
    imagedestroy($image);
}

// 使用示例
adjustContrast('original_image.jpg', 1.5); // 將對比度增加1.5倍

以上代碼通過遍歷圖片的每個像素，獲取原始RGB值并根據(jù)指定的對比度值計算新的RGB值，然后使用imagesetpixel

?? ?? ??
????? RGB ? ??? ???? ?? ??? ??? ? ????. ??? PHP GD ?????? ???? ???? ??? ???? ?? ?????. ??rrreee??? ??? ???? ? ??? ???? ?? RGB ?? ?? ??? ?? ?? ???? ? RGB ?? ??? ?? imagesetpixel ??? ???? ? ?? ?? ?????. ????? ??? ??? ?????. ????PHP? ???? ???? ??? ??? ???? ???? ????? ? ?? ??? ?? ??? ???? ? ?? ??? ??? ?? ? ????. ? ??? ?? ??? ? ??? ???? ? ??? ??? ????. ??

? ??? PHP? ???? ???? ??? ??? ???? ??? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!