What is claimed is:1. An image processing apparatus for estimating a printing result to be obtained by printing input image data with a printer, the image processing apparatus comprising:one or more memories storing instructions; andone or more processors executing the instructions to function as:an obtaining unit configured to obtain the input image data;an estimation unit configured to estimate, as the printing result, information on at least one of scattering or bleeding of a color material in the printing of the input image data with the printer based on the input image data;an intermediate data obtaining unit configured to obtain intermediate data generated from scanned image data;a first learning unit configured to, by using a combination of the input image data and the intermediate data associated with the input image data, cause a first estimator included in the estimator to perform learning; anda second learning unit configured to, by using a combination of the intermediate data and the scanned image data associated with the intermediate data, cause a second estimator included in the estimator and being different from the first estimator to perform learning,wherein the estimation unit has been caused to learn the scanned image data as correct data, the scanned image data being obtained by reading, with a scanner, a printing result obtained by printing an image data with the printer.2. The image processing apparatus according to claim 1, whereinthe estimation unit comprises:a first estimation unit configured to estimate intermediate data based on the input image data; anda second estimation unit configured to estimate the printing result based on a result of the estimation by the first estimation unit.3. The image processing apparatus according to claim 2, wherein the intermediate data is image data with a smaller number of tone levels than that of estimated image data outputted as the result of the estimation by the second estimation unit.4. The image processing apparatus according to claim 2, wherein the intermediate data is image data indicating a region in the printing result in which a color material is applied at a predetermined density or higher.5. The image processing apparatus according to claim 4, wherein the intermediate data is binary image data in which a single pixel is expressed by 1 bit.6. The image processing apparatus according to claim 2, wherein the first estimation unit and the second estimation unit each comprise a neural network.7. The image processing apparatus according to claim 1, further comprising a display configured to display estimated image data outputted by the estimation unit as a result of the estimation of the printing result.8. The image processing apparatus according to claim 1, wherein the input image data is binary image data.9. The image processing apparatus according to claim 1, whereinthe correct data is obtained by reading, with a scanner, a printing result obtained by printing a plurality of pieces of binary image data with the printer,the plurality of pieces of binary image data are obtained by performing halftoning on a plurality of pieces of multi-tone image data, andthe plurality of pieces of multi-tone image data include pieces of image data with different numbers of tone levels.10. A learning apparatus comprising:one or more memories storing instructions; andone or more processors executing the instructions to function as:a first obtaining unit configured to obtain learning input image data;a second obtaining unit configured to obtain scanned image data obtained by reading, with a scanner, a printing result obtained by printing the learning input image data with a printer;a learning unit configured to, by using a combination of the learning input image data and the scanned image data, cause an estimator to perform learning, the estimator being configured to estimate a printing result to be obtained by printing input image data with the printer; andan intermediate data obtaining unit configured to obtain intermediate data generated from the scanned image data,wherein the estimator estimates, as the printing result, information on at least one of scattering or bleeding of a color material in the printing of the input image data with the printer, andwherein the learning unit comprises:a first learning unit configured to, by using a combination of the input image data and the intermediate data associated with the input image data, cause a first estimator included in the estimator to perform learning; anda second learning unit configured to, by using a combination of the intermediate data and the scanned image data associated with the intermediate data, cause a second estimator included in the estimator and being different from the first estimator to perform learning.11. The learning apparatus according to claim 10, wherein the intermediate data is obtained by converting the scanned image data into image data with a smaller number of tone levels than that of the scanned image data.12. The learning apparatus according to claim 10, wherein the learning input image data and the input image data are binary image data.13. The learning apparatus according to claim 10, whereinthe learning input image data is a plurality of pieces of binary image data obtained by performing halftoning on a plurality of pieces of multi-tone image data, andthe plurality of pieces of multi-tone image data include pieces of image data with different numbers of tone levels.14. An image processing method of estimating a printing result to be obtained by printing input image data with a printer, comprising:obtaining the input image data;estimating, as the printing result, information on at least one of scattering or bleeding of a color material in the printing of the input image data with the printer based on the input image data;obtaining intermediate data generated from scanned image data,wherein estimation of the information is performed by an estimator that has been caused to learn the scanned image data as correct data, the scanned image data being obtained by reading, with a scanner, a printing result obtained by printing an image data with the printer, andwherein causing the estimator to perform learning includes:by using a combination of the input image data and the intermediate data associated with the input image data, causing a first estimator included in the estimator to perform learning; andby using a combination of the intermediate data and the scanned image data associated with the intermediate data, causing a second estimator included in the estimator and being different from the first estimator to perform learning.15. A learning method comprising:obtaining learning input image data;obtaining scanned image data obtained by reading, with a scanner, a printing result obtained by printing the learning input image data with a printer;by using a combination of the learning input image data and the scanned image data, causing an estimator to perform learning, the estimator estimating a printing result to be obtained by printing input image data with the printer; andobtaining intermediate data generated from the scanned image data,wherein the estimator estimates, as the printing result, information on at least one of scattering or bleeding of a color material in the printing of the input image data with the printer, andwherein causing the estimator to perform learning includes:by using a combination of the input image data and the intermediate data associated with the input image data, causing a first estimator included in the estimator to perform learning; andby using a combination of the intermediate data and the scanned image data associated with the intermediate data, causing a second estimator included in the estimator and being different from the first estimator to perform learning.16. A non-transitory computer readable storage medium storing a program which causes a computer to execute an image processing method of estimating a printing result to be obtained by printing input image data with a printer, the image processing method comprising:obtaining the input image data;estimating, as the printing result, information on at least one of scattering or bleeding of a color material in the printing of the input image data with the printer based on the input image data;obtaining intermediate data generated from scanned image data;by using a combination of the input image data and the intermediate data associated with the input image data, causing a first estimator included in the estimator to perform learning; andby using a combination of the intermediate data and the scanned image data associated with the intermediate data, causing a second estimator included in the estimator and being different from the first estimator to perform learning,wherein estimation of the information is performed by an estimator that has been caused to learn scanned image data as correct data, the scanned image data being obtained by reading, with a scanner, a printing result obtained by printing an image data with the printer.17. A non-transitory computer readable storage medium storing a program that causes a computer to perform a method comprising:obtaining learning input image data;obtaining scanned image data obtained by reading, with a scanner, a printing result obtained by printing the learning input image data with a printer;by using a combination of the learning input image data and the scanned image data, causing an estimator to perform learning, the estimator estimating a printing result to be obtained by printing input image data with the printer;obtaining intermediate data generated from scanned image data;by using a combination of the input image data and the intermediate data associated with the input image data, causing a first estimator included in the estimator to perform learning; andby using a combination of the intermediate data and the scanned image data associated with the intermediate data, causing a second estimator included in the estimator and being different from the first estimator to perform learning,wherein the estimator estimates, as the printing result, information on at least one of scattering or bleeding of a color material in the printing of the input image data with the printer.