I did it but the result is really not satisfying when the image is too big.
Indeed for an image of 82x1000 pixels, we need to reduce it to 64x780 pixels then crop the image to 64x64 pixels.
So a too big piece of the picture is lost (780-64= 716 pixels !) and the image in gallery does not represent the real image. Sometimes all the images of the gallery are the same because the first 64 pixels are identical.
We could choose to crop to 64x64 pixels from the center of the image, but there is no guarantee that the generated image will be more representative.
However, when the image height or width is smaller than 64 pxiels, the image will be zoom then crop to 64x64pixels. The result is better in this case.
Improvement
Minor
I did it but the result is really not satisfying when the image is too big.
Indeed for an image of 82x1000 pixels, we need to reduce it to 64x780 pixels then crop the image to 64x64 pixels.
So a too big piece of the picture is lost (780-64= 716 pixels !) and the image in gallery does not represent the real image. Sometimes all the images of the gallery are the same because the first 64 pixels are identical.
We could choose to crop to 64x64 pixels from the center of the image, but there is no guarantee that the generated image will be more representative.
However, when the image height or width is smaller than 64 pxiels, the image will be zoom then crop to 64x64pixels. The result is better in this case.