Not support YCbCr photometric interpretated GeoTIFF(COG)!

[ChangmingWang]

It occurs error message like "Invalid or unsopported photometric interpretation" when loads GeoTIFF generated by YCbCr photometric interpretation (as picture below).

It is supported with OpenLayers API to load YCbCr photometric interpretated GeoTIFF.

YCbCr photometric interpretated GeoTIFF can be downloaded at the link below.

https://oin-hotosm.s3.us-east-1.amazonaws.com/66b62bc67f12df0001cdd091/2/66b62bc67f12df0001cdd094.tif

[a13668349935]

I found the problem. The core reason is that there is a mask in the YCbCr tiff. I solved the problem by eliminating the mask, but in openlayers, the image and mask are merged in the loadTile function. I didn't merge them here, and I don't know how to merge them, but it doesn't seem to make any difference. I'll post the core code
_build function limits the imagecount.
this._imageCount = await source.getImageCount();
for (let i = 0; i < this._imageCount; i++) {
const img = await source.getImage(i);
if (this._isMask(img)) {
// console.warn(Image ${i} is a mask image, skipping...);
this._masks.push(img);
}
else {
this._images.push(img);
}
}
this._imageCount = this._images.length;
Add this function, I copied it from ol.
private _isMask(image: GeoTIFFImage): boolean {
const fileDirectory = image.fileDirectory;
const type = fileDirectory.NewSubfileType || 0;
return (type & 4) === 4;
}
Then, in the subsequent requests for images, they are directly taken from _images, including the
_getCogLevels and _loadTile functions
const image = this._images[i] ; //_getCogLevels()
let image = this._images[index];//_loadTile ()
This way, my test has passed

[hongfaqiu]

@a13668349935 Thank you for finding the problem so quickly! This is an elegant solution. If possible, you can submit a PR to this repository. I will approve it as soon as possible to automatically update the npm package.