Method for providing thermal transfer image data, method for forming images, and image display device

A method for providing thermal transfer image data, the thermal transfer image data being used to transfer part of a transfer material layer in a transfer ribbon to an image-receiving layer to form therein an image comprising a plurality of image cells, comprising:

• obtaining a multitone input image having a plurality of input tone values;
• dividing the input image into a plurality of interleaved regions, each of which corresponds to an input tone value of said plurality of input tone values;
• converting the multitone input image into a multitone image having a plurality of output tone values, wherein a number of the output tone values is less than a number of the input tone values, such the converted image comprises a plurality of extended regions, each of which a) corresponds to an output tone value of said plurality of output tone values and b) extends over multiple interleaved regions of the input image;
• dividing the input tone values of the input image into a low-tone-value range, an intermediate-tone-value range, and a high-tone-value range;
• in the low-tone-value range, setting a low tone value replacement amount to continuously increase with decreasing of the tone value;
• in the high-tone-value range, setting a high tone value replacement amount to continuously increase with increasing of the tone value;
• and
• in the intermediate-tone-value range, setting an intermediate-tone value replacement amount to be 0;
• and,
• dithering each of the extended regions to provide the thermal transfer image data, said dithering comprises adding a corresponding replacement amount to the output tone value of the extended region for a first interleaved region and subtracting the replacement amount from the output tone value of the extended region for the second interleaved region.