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| input.addEventListener("change", function(){
var file = this.files[0];
// 接受 jpeg, jpg, png 类型的图片
// if (!/\/(?:jpeg|jpg|png)/i.test(file.type)) return;
var reader = new FileReader();
var compressCanvas = document.querySelector(".babyhappy_compressimg_con");
compressCtx = compressCanvas.getContext("2d");
reader.onload = function(event) {
var result = this.result;
var image = new Image();
image.src = reader.result;
image.onload = function(){
EXIF.getData(image, function(){
EXIF.getAllTags(this);
var orientation = EXIF.getTag(this, 'Orientation');
switch(orientation){
case 1:
//0°
compressCanvas.height = image.height;
compressCanvas.width = image.width;
compressCtx.clearRect(0, 0, compressCanvas.width, compressCanvas.height)
compressCtx.drawImage(image, 0, 0, image.width, image.height);
break;
case 6:
//顺时针90°
compressCanvas.width = image.height;
compressCanvas.height = image.width;
compressCtx.clearRect(0, 0, compressCanvas.width, compressCanvas.height)
compressCtx.translate(0, 0);
compressCtx.rotate(90 * Math.PI / 180);
compressCtx.drawImage(image, 0, -image.height, image.width, image.height);
break;
case 8:
//逆时针90°
compressCanvas.width = image.height;
compressCanvas.height = image.width;
compressCtx.clearRect(0, 0, compressCanvas.width, compressCanvas.height)
compressCtx.translate(0, 0);
compressCtx.rotate(-90 * Math.PI / 180);
compressCtx.drawImage(image, -image.width, 0, image.width, image.height);
break;
case 3:
//180°
compressCanvas.height = image.height;
compressCanvas.width = image.width;
compressCtx.clearRect(0, 0, compressCanvas.width, compressCanvas.height)
compressCtx.translate(0, 0);
compressCtx.rotate(Math.PI);
compressCtx.drawImage(image, -image.width, -image.height, image.width, image.height);
break;
default:
compressCanvas.height = image.height;
compressCanvas.width = image.width;
compressCtx.clearRect(0, 0, compressCanvas.width, compressCanvas.height)
compressCtx.drawImage(image, 0, 0, image.width, image.height);
}
var base64 = compressCanvas.toDataURL("image/jpeg", .5);
})
}
reader.readAsDataURL(file);
}, false)
|
