Image processing apparatus, printing system, and image processing method for thin line processing

An image processing apparatus configured to execute image processing for acquiring a converted image of which a resolution is converted based on an input image including a plurality of pixels arranged in a first direction and in a second direction intersecting the first direction, the image processing apparatus comprising:

• a blurring processing unit configured to generate a blurred image by applying, to the input image, a two-dimensional Gaussian filter having a first filter size in the first direction and a second filter size in the second direction;
• and
• a resolution conversion unit configured to generate, from the blurred image, the converted image of which the resolution is converted at a first conversion magnification that is a conversion magnification of the resolution in the first direction and at a second conversion magnification that is a conversion magnification of the resolution in the second direction,
• wherein the second conversion magnification is larger than the first conversion magnification when the blurring processing unit makes the first filter size larger than the second filter size,
• the first conversion magnification is larger than the second conversion magnification when the blurring processing unit makes the second filter size larger than the first filter size,
• a standard deviation σ of the Gaussian filter in the first direction is set to be a standard deviation σ1,
• a standard deviation σ of the Gaussian filter in the second direction is set to be a standard deviation σ2, and
• the blurring processing unit applies, to the input image, the Gaussian filter having a filter coefficient in which the standard deviation σ2 is equal to the standard deviation σ1 when the second filter size is different from the first filter size.