Image recording apparatus having a small-capacity frame memory and an image recording method

An image recording method comprising the steps of:

• (a) when an image represented by image data is expressible as an image having a small number of pixels per unit area, storing second image data in second storage means for storing image data having a small number of pixels per unit area and a large number of gradations per pixel, and when the image represented by image data is not expressible as an image having a small number of pixels per unit area, storing first image data in first storage means for storing image data having a large number of pixels per unit area and a small number of gradations per pixel;
• (b) converting the first image data stored in said first storage means to converted image data having a large number of gradations per pixel, and converting the second image data stored in said second storage means to converted image data having a large number of pixels per unit area;
• and
• (c) recording a final image in accordance with the first converted image data and the second converted image data.

An image recording apparatus comprising:

• recording means for recording an image in accordance with image data having a large number of pixels per unit area and a large number of gradations per pixel;
• first storage means for storing first image data having a large number of pixels per unit area and a small number of gradations per pixel;
• second storage means for storing second image data having a small number of pixels per unit area and a large number of gradations per pixel;
• determining means for determining whether or not an image represented by the image data can be expressed as an image having a small number of gradations per pixel, whereby when it is determined that the image represented by the image data can be so expressed, the image data is stored in said first storage means, while when it is determined that the image represented by the image data cannot be so expressed, the image data is stored in said second storage means;
• and
• a first converting means for converting the first image data stored in said first storage means to converted image data having a large number of gradations per pixel, and a second converting means for converting the second image data stored in said second storage means to converted image data having a large number of pixels per unit area, so as to supply the first converted image data and the second converted image data to said recording means.

An image recording apparatus comprising:

• recording means for recording an image in accordance with image data having a large number of pixels per unit area and a large number of gradations per pixel;
• first storage means for storing first image data having a large number of pixels per unit area and a small number of gradations per pixel;
• second storage means for storing second image data having a small number of pixels per unit area and a large number of gradations per pixel;
• determining means for determining whether or not an image represented by the image data can be expressed as an image having a small number of pixels per unit area, whereby when it is determined that the image represented by the image data can be so expressed, the image data is stored in said second storage means, while when it is determined that the image represented by the image data cannot be so expressed, the image data is stored in said first storage means;
• and
• a first converting means for converting the first image data stored in said first storage means to first converted image data having a large number of gradations per pixel, and a second converting means for converting the second image data stored in said second storage means to second converted image data having a large number of pixels per unit area, so as to supply the first converted image data and the second converted image data to said recording means.